The Round Tower: Historic Observatory of Copenhagen, Denmark

The Round Tower (Rundetaarn) rises in the heart of Copenhagen’s old Latin Quarter, with its entrance on Købmagergade in the Indre By district. It is a short walk from both the Round Tower’s neighbouring shops and the Strøget shopping street, and the nearest transport hub is Nørreport station, about six minutes away on foot, served by the Metro, S-trains, and regional trains. Several city bus lines also stop nearby. Because of its central position, it pairs naturally with a visit to Rosenborg Castle and the King’s Garden close by.

History and What Makes It Unique

Built between 1637 and 1642 by King Christian IV, the Round Tower formed part of the Trinitatis Complex, which combined a church, a library, and an observatory in a single building. It is the oldest functioning observatory in Europe, originally used by University of Copenhagen astronomers to study the night sky above the city. Its most distinctive feature is the spiral ramp, the only one of its kind in Denmark, which winds seven and a half times around the tower’s hollow core instead of using stairs. Halfway up, the beautiful Library Hall now hosts changing exhibitions and concerts, and from the viewing platform at the top there is a 360-degree panorama over Copenhagen’s spires and rooftops.

Tickets and Practical Information

Admission is 60 DKK for adults and 40 DKK for students, while children under 18 enter free. Tickets can only be bought on the spot at the tower; ordinary entry tickets cannot be purchased in advance, and credit cards are preferred. Importantly, the Round Tower is no longer included in the Copenhagen Card. Wait times rarely exceed about 20 minutes even at peak hours, as staff manage the flow of visitors. Travellers should note that the tower’s observatory and telescope are undergoing restoration during 2026, which affects access to the very top, so it is worth checking the official website before visiting. The ramp is easy to walk, but there is no lift, so it is not accessible by wheelchair.