Formerly known as Stellaburgis Hafniens, the Round Tower is a 17th-century tower astronomical observatory, most famous for its equestrian staircase. It is the oldest observatory in Europe still functioning, and one of the top places to visit in Copenhagen offering an expansive view of old Copenhagen.
You can see the core of the tower from a glass floor hanging above the floor and you can also visit the library hall inside the tower, which now holds exhibitions about art, culture, history, and science.
Location: Købmagergade 52A, 1150 København, Denmark
Entry fees: 25 DKK per head