20 Places to Visit in Reykjavík , Tourist Places & Attractions

Places to Go in Reykjavik

Hallgrímskirkja Church, Downtown, Harpa Reykjavik Concert Hall, Thermal Pools, The Settlement Exhibition, Mount Esja, Perlan Museum of Icelandic Natural Wonders, National Museum of Iceland and many more

Often referred to as the oasis of peace, a location filled with richness and history and home to numerous scenic abodes, one will find many beautiful places to visit in Iceland Reykjavik. No matter whether you amble down the downtown streets, go out for a sightseeing excursion or dip in thermal hot springs, you will get the best moments to ever live in your life.

Many places to go in Reykjavik like the Mount Esja and the Videy Island are known to offer a proper natural encounter. With their splendid beauty and array of activities on exhibit, these places have been attracting flocks of tourists throughout the world. Even after being a small city, Reykjavik remains home to more than 400 cathedrals and around 65 parks. The colorful coastal homes, vibrant art and culture, and the rich Viking history will definitely startle you. This city is a mecca of contemporary architecture and cultural fusion which can be easily seen at most beautiful places in Reykjavik .While most of its area remains closer to the coast, you will alway remain in a close vicinity of a beach and will surely enjoy numerous water based adventures.

Here's the list of best places to visit in Reykjavik:

Image description
Bigger Group? Get special offers upto 50% off!
We create unforgettable adventures, customised for your group.
Connect with a group tour expert
Full Name
Email
Phone number
Travel Date
Traveller Count
Message
Explore All (23)
About: The Hallgrímskirkja Church is one of the most notable places to visit in Iceland Reykjavik. Enjoy the immersive building that offers a blend of beauty, history, and magnificent architecture. Located in the heart of the city, the Hallgrímskirkja Church dominates Reykjavik's skyline.

The iconic church was built as an homage to the Icelandic poet, Hallgrímur Pétursson. It seems omnipresent from anywhere in Reykjavik. The 25-ton pipe organ is a majestic piece to see. Don’t miss the chance to visit the unique white-concrete statue when you are here. Look for the elevator to climb up 74 meters to the turret to get a splendid view of the city.

Location:
Hallgrímstorg 1, 101 Reykjavík, Iceland.

Price:
$8 entree fee (adults).

Timing:
9 AM to 5 PM (Winter) & 9 AM to 9 PM (Summer).

Best Time to Visit:
June to August.
Read more
Plan your visit to Downtown Reykjavik to feel the ambiance of a small town filled with wonky little houses and comfy restaurants. The place is home to stand-alone boutiques selling exquisite items like Icelandic wool clothing and volcanic rock pottery. Don’t miss the palatable servings from the exotic eateries here.

Go for a walk through the evening to feel the ocean breeze at the waterfront walkway. The fine art and architecture will just cheer you up. As it gets dusky, hurry up for the solfar sculpture to see the most exuberant sunsets you will ever see in Iceland.

Location: Centre, 101 Reykjavik, Iceland.

Price: $100-$251 per day per person.

Timing: 10 AM to 8 PM.

Best Time to Visit: June to August.
Read more
Harpa is a one-stop cultural and social center in the middle of the city. The concert hall is a tantalizing destination for riveted travelers and has enticed over 10 million guests since its inception in 2011. The concert hall displays an artistic honeycomb exterior that is a delight to the eyes.

It serves dualistic purposes for the visitors, extraordinary in the daylight, and changing windows with rainbow colors mesmerizes the nighttime explorers too. Explore a range of options of Nordic design, flowers, and other eminent gift items at the Harpa shops when you are here.

Location: Harpan, 101 Reykjavik, Iceland.

Price: $5

Timing: 8 AM to 12 AM.

Best Time to Visit: July to August.
Read more
Attractions Explore All (5)
When it comes to finding the prominent places to visit in Iceland Reykjavik, thermal pools are the best pick for you. Walk through the city to find the best geothermal pool for yourself.  The city of Reykjavik has 17 thermal pools around the city filled with natural geothermal water springs.

These pools are community socializing spots and offer a natural healing therapy for the body, mind, and soul. Immerse yourself into the soaking custom of bathing into thermal pools. The open community pools form an inevitable part of the Icelandic culture and offer exceptional healing qualities. Go for the Blue Lagoon trip to take back an enthralling pool experience for your home.

Location: Blue Lagoon, Grindavik, Iceland

Price: $41 per person

Timing: 6 AM to 11 PM

Best Time to Visit: October to April
Read more
It is a great stop for curious globetrotters willing to learn more about the early settlers of Iceland. The exhibition walks tourists through an excavated farmhouse dating back to 871 AD. Take the interactive display tour and artifact cases to gain more insights into the Viking settlement life.

Digital interactive displays help you see the primitive Icelandic life and instill a note of appreciation for the Viking influences. The preserved artifacts will serve you with enough evidence to delve deeper into the Vikings' story. The Settlement Exhibition is located at the Adalstraeti 16. It rests near the Viking longhouse archaeological site. 

Location: Aðalstræti 16, 101 Reykjavík, Iceland.

Price: $15 per person.

Timing: 9 AM to 6 PM.

Best Time to Visit: September to mid-April.
Read more
The majestic aura of Mount Esja Makes it one of the most beautiful places in Reykjavik that you could ever find during your Iceland trip. Mountain Esja is the crown jewel in Reykjavik’s skyline and is known for offering a hiking turf for both locals and tourists alike.

For tourists, Esja is a natural workout station, with acute slopes testing your strength in every step, and its majestic views making it all worthwhile. The flat-topped 914 meters high mountain is 6.21 miles from the capital city of Reykjavik. The mountain hike is for both casual and pro hikers. However, limit yourself to going above the Steinn point. As beyond this point, it is a choice limited to experienced climbers and hikers only.

Location: Þverfellshorn ranges, Iceland.

Price: $282 entree fee.

Timing: 6 AM to 5 PM.

Best Time to Visit: November to March.
Read more
Adventure Explore All (8)

The National Museum of Iceland is a modern and progressive experience that provides an insight into Iceland‘s past 1200 years of cultural history. The museum was opened on 24th February 1863 as Antiquarian Collection and was housed in several buildings in Reykjavik, before being housed in the current building at Suðurgata Street in 1944.

Read more

Fun, mesmerizing, and full of surprises, this living museum walks you on a journey of time. Arbaer Open-Air Museum is a small village outside the city. It takes over an hour from Reykjavik to reach but is worth visiting. You can find the old houses at the museum and understand the lifestyle of the old Reykjavik.

Don’t miss the Arbaer turf farm, the only existing turf farm in the capital city. Enjoy the history of Reykjavik preserved in more than 20 restored historical old homes. The museum is open all year round to take guided tours in it.

Location: 4, 110, Kistuhylur, Reykjavík, Iceland.

Price: $13 (adults).

Timing: 10 AM to 5 PM.

Best Time to Visit: January to December.
Read more
Day Tours Explore All (40)
Explore All (40)
The Sun Voyager (Sólfarið) is a large steel carving of a ship, definitely worth a visit for voyagers. It is the most touristic display where flocks of people come together to see the sun reflection in the steel model. Located on the Sæbraut road, the seaside model of central Reykjavik displays a perfect blend of art and nature.

The stunning display offers a great photo opportunity with the sea all over and mountains at the back. The monument displays, “the promise of undiscovered territory, a dream of hope, progress, and freedom.” Include Sun Voyager in your bucket list of places to go in Reykjavik.

Location: Sæbraut, 101 Reykjavík, Iceland.

Price: $12 (entree fee).

Timing: 4 PM to 7 PM.

Best Time to Visit: Mid-May to late-July.
Read more

Snorralaug is a historical geothermal pool nestled in Reykholt, Iceland. Regarded as the oldest known hot springs in the country, it boasts a rich history that dates back to the medieval era. The pool is named after a popular Icelandic poet, historian, and chieftain named Snorri Sturluson, who belonged to the 13th century. Earlier, Snorri used the hot spring for different rituals and bathing as it offered endless healing possibilities. When you travel to Snorralaug, there is a circular stone pool surrounded by a well-preserved stone wall, adding more to its glory. 

Read more
The Old Harbour area will give you a glimpse of Icelandic culture as this part of the city offers amazing sights of bays and Mount Esja. Here, you can enjoy the eclectic views of the ocean from any of the water-faced restaurants, the boats, the gusto of a working harbor, and the aura of the sea.

This cosmopolitan area is a hub of sumptuous seafood bistros, fancy design boutiques, souvenirs, and coffee shops, and all these factors make it one of the most beautiful places in Reykjavik. In the Old Harbour Area, you can enjoy pre-dinner drinks and meals trailed by the whale and birdwatching tours. It is quite easy to reach the Old Harbour area within a few minutes of walking from the city center. 

Location: Geirsgata 5c, 101 Reykjavík, Iceland.

Price: $26 - $50 per person.

Timing: 8 AM to 9 PM.

Best Time to Visit: June to August.
Read more
An island where art, history, and nature fuse together to finally present the visitor with a peaceful surrounding.The island offers a blend of esthetic views, historical remains, and modern art pieces all within a small vicinity from each other.

The Videy island sits off the coast of Reykjavik with beautiful artworks and intrinsic natural beauty. Due to its smaller size, the island is easy to explore on foot and by bike. You can even take a short boat ride to enter another dimension of peace and joy. The place is an exotic destination for photographers and artists to explore the abundance of wildlife and vegetation.

Location: Videy, Iceland.

Price: $35 - $50 (entree fee).

Timing: 8 AM to 6 PM.

Best Time to Visit: April to September.
Read more
Bruarfoss is one of the most beautiful places in Reykjavik due to the serenity which surrounds it. Bruarfoss, is named after the stone archway that crisscrossed the river once and this waterfall is famed for radiating an oceanic blue color.

In fact, it is celebrated as “Iceland’s Bluest Waterfall.” To get here, you have to cover a round-trip hike of 7 km (4.4 miles) towards the west of Iceland, which is over an hour’s journey from east of Reykjavik. The hike offers an array of smaller waterfalls on display, however the Bruarfoss is clearly the big show here.

Location: Brekkuskógur, Road 355, Iceland, Reykjavik.

Price: $50 per person.

Timing: 9 AM to 4 PM.

Best Time to Visit: June to September.
Read more
Grotta Lighthouse is a nature reserve on the top of the Seltjarnarnes Peninsula. The place offers a great place to take a casual walk and move out from the hustle and bustle of Reykjavik city. Quite popular for the amazing Northern Lights, make sure to catch hold of the glimpses of it.

The spot is home to a variety of bird species, making it an ideal place for birdwatching. Grotta Lighthouse is on the outskirts of Reykjavik city and is a prime sightseeing location. Access the lighthouse during low tides, as it is hard to reach the spot during high tides. 

Location: Grótta Island Lighthouse, Iceland, Seltjarnarnes, Iceland.

Price: $4 (bus ticket).

Timing: 6 PM to 12 AM.

Best Time to Visit: June to August.
Read more
Reykjavík Tours Explore All (6)

The City Hall Reykjavik was built in 1992 after a design competition and is a crucial landmark in the city. This is a building that comes with modern Nordic design with traditional icelandic materials and is also known for existing on a body of water known as Tjornin. This building houses the office of the Mayor of Reykjavik and also the city’s official tourist information centre. 

Read more

The Ytri Tunga Beach is located on the southern side of the Snaefellsnes peninsula of Iceland. This is a place which is known for the stunning natural beauty and is now for the shiny golden sand. 

Read more

Laugavegur, Reykjavík’s most iconic shopping street, seamlessly blends urban charm with Icelandic culture. Spanning a little over a kilometer, this lively thoroughfare is the heartbeat of the city’s shopping and entertainment scene. Lined with a vibrant mix of boutiques, bookstores, and specialty shops, Laugavegur caters to both locals and visitors. Fashion enthusiasts can explore a range of trendy stores showcasing Icelandic designers and unique clothing. Art lovers will find galleries featuring local talent, while those seeking souvenirs can browse handcrafted goods and traditional Icelandic items.

Read more
Things to do in Reykjavík Explore All (34)
Explore All (34)

Raufarholshellir is the fourth longest cave in the world and is located 30 minutes from Reykjavik, the capital of Iceland. This cave was formed many years ago due to activities from volcanoes, and ever since then, it has attracted a lot of tourists. The Raufarholshellir hosts different types of cave tours where you can explore this natural wonder and discover interesting landscapes. 

Read more

People Also Ask About Reykjavík

  1. Which are the best places to visit in Reykjavik?

    1. Golden Circle: Golden Circle 300 km area of the city in which three major places to visit in Iceland Reykjavik are covered - the Gullfoss Waterfall, Pingvellir National Park, and the Haukadalur geothermal hot springs and geysers.

    2. Harpa: Cherish the stunning architectural beauty of Harpa and immerse yourself in the live shows and concerts for an entire day. It offers exquisite boutiques and lavish dining options, putting it under the chart of top places to go in Reykjavik.
     
    3. Akurey: Take a short trip to Akurey for bird watching. Enjoy the native blend of Icelandic species with glimpses of puffins and various other seabirds like gulls, terns, and fulmars.
     
    4. Reykjanes Peninsula: This peninsula is full of active lava fields, hot springs, and volcanic craters. In addition to this, one will also find numerous museums and churches with amazing landscapes which are considered to be some of the best Reykjavik places to visit in Iceland.
  2. What can you do for free in Reykjavik?

    1. Take a walking tour of the city: One of the best ways to explore any city is by taking its walking tour and covering major tourist attractions on foot. While in Reykjavik, you can easily cover locations like Videy Island, Grotta Lighthouse and Sun Voyager easily. 

    2. Explore a beach: Being a coastal city, Reykjavik will bestow you with a million chances to stay close to the beaches and enjoy seaside activities on your own. For more fun, you can choose to sit by seaside and gaze into the uninterrupted views of the setting sun. 

    3. Blue Lagoon Dip: Take a dip at the blue lagoon to enjoy the geothermal spa experience in thermal pools and waterfalls. 
    Blue Lagoon is a top choice among tourists on the list of Reykjavik places to visit.

    4. Watch Northern Lights: You can take your personal vehicles to various spots where watching the Northern Lights is easy to enjoy this free activity. The coasts are the best places to offer a clear sky and broad horizon perfect for viewing aurora light experiences.
  3. Which are the places to visit in Reykjavik for Northern lights?

    1. Reykjavik Boat Cruise: Take a boat trip from the harbor to view the dancing lights on top of the ocean. Clear skies and quiet seas are a must-have combo for it. Dropping the boat trip from the list of Reykjavik places to visit is unthinkable.

    2. Pingvellir National Park: Go to the National Park of Pingvellir to see the aurora experience. The place offers minimal light pollution and a clear sky.

    3. Jokulsarlon: Include the glacial lagoon trip on your bucket list to feel the unique landscape and explore the northern lights. This is a must-visit place for artists and photographers.

    4. Reynisfjara Black and Sand Beach: Take out some time from your trip to discover the dramatic views and sound of the waves. The basalt stacks offer a front-row seat to the extraordinary light show. This sandy beach is a few of the unique places to visit in Iceland Reykjavik, and in the whole of Europe.
  4. Is Reykjavik expensive to visit?

    Reykjavik is an expensive city with higher travel costs for tourists. For an adult, the average cost for a trip to Reykjavik can cost anywhere between ?100,000 to ?160,000 for a week. This amount will include a stay, food, travel and transportation costs.
  5. What is famous in Reykjavik?

    Reykjavik, the coastal city of Iceland is known for its thriving nightlife, vibrant culture and rich history. This place is also known for offering a plethora of on land and water based activities to the tourists. Having a smaller area, the places to visit in Iceland Reykjavik make it easy for bar crawlers to have fun while bar hopping.
Newly Added Reykjavík Experience
Excellent
All investment we had on this tour truly worth everything any way the beauty of the place already worth every penny we spend. The itinerary of the trip was very rich, fulfilling, and satisfying right from day one till the last day of our trip... The hotel they provided for us was luxury and everything was well arranged and on time... All the day tours were amazing and we covered it all as mentioned on the itinerary... Every day we had an awesome day with lots of amazing expereince... Nice people and breathtaking place this Will definitely worth recommending others...
Excellent
It was really the top and memorable place we had visited till now and we had a great time on this tour... Which is with no regret will always recommend this trip to everyone especially to all the traveller this is the best place you'll find so much amazing views with lots of natural scenics beauty everywhere... Really I am in love with the place each sightseeing we visited truly gave us surprises and good photos... The accommodations were great and the hotel staffs were very professional and helpful... We get to learn about the culture and history of the place which was very interesting... The picked-up and dropped-off were on time really all the arrangements exceeded our expectations. The visiting to volcanoes, waterfall, black sand beached and lava centre had made us excited... 10 days spent in Iceland was really a mind-blowing experience we had once in a lifetime...
Excellent
I was thrilled with my trip, Not sure where to start but this trip we choose again this time with Thrillophilia was quite an interesting and exciting one...The trip was pre-planned way ahead of time to accommodate our vacation for the lasts 4 months before the date of travel while planning our trips they make sure and informed us everything with new ideas about the trip which we are happy with their plan...On this trip since our landing on this place, we were received by a professional and punctual driver...The trip went so smooth and we were guided by the professional who was helpful and great at rectifying situations...We had been looking out for the entire trip to make sure that we are comfortable with the trip we had and also that we discovered all the major attractions as per the planned decided...The place is truly breathtaking and has lots to see which was truly worth-seeing...The Self-drive trip was the best part of our trip being in a different country but still, we roam the place like a local that's the biggest expereince we had...Overall all the arrangements were taken care of nicely and we love everything provided to us...
Excellent
The overall service provided by Thrillophilia was Excellent!!! Coordination of the overall trip in Iceland was superb and their choice of hotel was met with our expectation... The team were totally helpful and kept us informed at each step of the planning phase and keep in touch with us all the time... Local driver arranged for us was on time and courteous... The place is truly beautiful as all the places we covered were truly lovely and gave us stunning pictures with great background... We thoroughly love this trip... 14 days explored the place was more than enough for us
I was totally in love with this trip, It was so well-organized and well-executed, all arrangements were beyond our expectations, the place has natural beauty everywhere which gave us good pictures in life for a lifetime memory, All the sightseeing places were truly interesting and each sight simply wow us, I worked with Thrillophilia agents over several months and they remained very pleasant and kind throughout the entire process. I would highly recommend booking with Thrillophilia as they take care of everything and you get to enjoy your vacation...Thank you so much for everything will get back with your team
Excellent
We booked this tour and were completely dependent on the planners and team regarding everything. Would recommend others too, Thrillophilia you are completely reliable!
Excellent
Iceland is one amazing place to visit. I visited with my friends and it was an experience one could never forget. Would definitely visit with the team again, admirable work.
Excellent
We booked this tour to Iceland and as we arrived the driver was waiting for us right there! Later as we traveled we got to know that Iceland has variety of places to visit like it has mountains, landscapes, seas everything. It has beautiful surroundings and nature. Also the accommodation and the staff there were really helpful and and friendly. Totally recommendable!
Excellent
We booked this tour to Iceland.We being the nature freaks this tour is a blessing for us,as it included the mountains, wildlife. It included everything the pick-up and drop were done on time by the driver and the accommodation was really good. The tour guide had enough knowledge of the places which always made us more curious.
Visiting South & West Iceland that with a self-drive tour for the span of 8-days was such a great tour we had...It will be complicated and you should ideally book everything months in advance since it was a long tour and it took time to planned and put all together what you are looking for on the trip...Thrillophilia was helpful in securing everything we needed...The place we discovered was breathtaking like waterfalls, glaciers, national parks, and lots more...The pre-booked hotel and transport were exactly as we wanted...The team was service-minded...My friends and I had a great time at this place.....

Places to Visit in India

Places to Visit in Delhi Places to Visit in Goa Places to Visit in Pune Places to Visit in Bangalore Places to Visit in Mumbai Places to Visit in Hyderabad Places to Visit in Jaipur Places to Visit in Chennai Places to Visit in Kolkata Places to Visit in Ladakh Places to Visit in Spiti Places to Visit in Andaman Places to Visit in Arunachal Pradesh Places to Visit in North East Places to Visit in Sikkim Places to Visit in Darjeeling Places to Visit in Meghalaya Places to Visit in Gangtok Places to Visit in Rajasthan Places to Visit in Uttarakhand Places to Visit in Kerala Places to Visit in Karnataka Places to Visit in Maharashtra Places To Visit In Himachal Pradesh Places to Visit in Madhya Pradesh Places to Visit in Kashmir Places to Visit in Manali Places to Visit in Dharamshala Places to Visit in Shimla Places to Visit in Mcleodganj Places to Visit in Nainital Places to Visit in Mussoorie Places to Visit in Dehradun Places to Visit in Rishikesh Places To Visit In Jammu Places to Visit in Srinagar Places to Visit in Chikmagalur Places to Visit in Munnar Places to Visit in Kodaikanal Places to Visit in Ooty Places to Visit in Pondicherry Places to Visit in Wayanad Places to Visit in Coorg Places to Visit in Mysore Places to Visit in Lonavala Places to Visit in Alibaug Places To Visit In Mahabaleshwar Places to Visit in Udaipur Places to Visit in Jodhpur Places to Visit in Jaisalmer Places to Visit in Mount Abu Places to Visit in Agra Places To Visit In South Goa Places To Visit In North Goa
Currency Picker
Commonly Used Currencies
INR -
Indian Rupee
USD - $
United States Dollar
EUR -
Euro
SGD - $
Singapore Dollar
AUD - $
Australian Dollar
GBP - £
British Pound
AED - د.إ
United Arab Emirates Dirham
All Other Currencies
ALL - L
Albanian Lek
AMD - դր.
Armenian Dram
ARS - $
Argentine Peso
AWG - ƒ
Aruban Florin
BBD - $
Barbadian Dollar
BDT -
Bangladeshi Taka
BMD - $
Bermudian Dollar
BND - $
Brunei Dollar
BOB - Bs.
Bolivian Boliviano
BSD - $
Bahamian Dollar
BWP - P
Botswana Pula
BZD - $
Belize Dollar
CAD - $
Canadian Dollar
CHF - CHF
Swiss Franc
CNY - ¥
Chinese Renminbi Yuan
COP - $
Colombian Peso
CRC -
Costa Rican Colón
CZK -
Czech Koruna
DKK - kr.
Danish Krone
DOP - $
Dominican Peso
DZD - د.ج
Algerian Dinar
EGP - ج.م
Egyptian Pound
ETB - Br
Ethiopian Birr
FJD - $
Fijian Dollar
GHS -
Ghanaian Cedi
GIP - £
Gibraltar Pound
GMD - D
Gambian Dalasi
GTQ - Q
Guatemalan Quetzal
GYD - $
Guyanese Dollar
HKD - $
Hong Kong Dollar
HNL - L
Honduran Lempira
HRK - kn
Croatian Kuna
HTG - G
Haitian Gourde
HUF - Ft
Hungarian Forint
IDR - Rp
Indonesian Rupiah
ILS -
Israeli New Sheqel
JMD - $
Jamaican Dollar
KES - KSh
Kenyan Shilling
KGS - som
Kyrgyzstani Som
KHR -
Cambodian Riel
KYD - $
Cayman Islands Dollar
KZT -
Kazakhstani Tenge
LAK -
Lao Kip
LBP - ل.ل
Lebanese Pound
LKR -
Sri Lankan Rupee
LRD - $
Liberian Dollar
LSL - L
Lesotho Loti
MAD - د.م.
Moroccan Dirham
MDL - L
Moldovan Leu
MKD - ден
Macedonian Denar
MMK - K
Myanmar Kyat
MNT -
Mongolian Tögrög
MOP - P
Macanese Pataca
MUR -
Mauritian Rupee
MVR - MVR
Maldivian Rufiyaa
MWK - MK
Malawian Kwacha
MXN - $
Mexican Peso
MYR - RM
Malaysian Ringgit
NAD - $
Namibian Dollar
NIO - C$
Nicaraguan Córdoba
NOK - kr
Norwegian Krone
NPR - Rs.
Nepalese Rupee
NZD - $
New Zealand Dollar
PEN - S/
Peruvian Sol
PGK - K
Papua New Guinean Kina
PHP -
Philippine Peso
PKR -
Pakistani Rupee
QAR - ر.ق
Qatari Riyal
RUB -
Russian Ruble
SAR - ر.س
Saudi Riyal
SCR -
Seychellois Rupee
SEK - kr
Swedish Krona
SLL - Le
Sierra Leonean Leone
SOS - Sh
Somali Shilling
SVC -
Salvadoran Colón
SZL - E
Swazi Lilangeni
THB - ฿
Thai Baht
TTD - $
Trinidad and Tobago Dollar
TZS - Sh
Tanzanian Shilling
UYU - $U
Uruguayan Peso
UZS - so'm
Uzbekistan Som
YER -
Yemeni Rial
ZAR - R
South African Rand
JPY - ¥
Japanese Yen
VND -
Vietnamese dong