The Round Tower

With its distinctive spiral ramp the Round Tower is one of Denmark’s best-known and most visited structures. A historical place that also houses exhibitions, concerts and activities for young and old.

The 17th-century tower and observatory Rundetaarn, or The Round Tower, is the oldest functioning observatory in Europe. It was built as a platform for the university observatory and for centuries it was the centre of Danish astronomy. The foundation stone was laid on July 7, 1637, and five years later the Round Tower was finished as the first part of the Trinity Complex, which was designed to accommodate three things: The observatory at the top of the tower, the university library above the Trinity Church and the church itself below.

The Round Tower is built by King Christian IV, who had the round walls constructed in the royal colours yellow and red. The King himself also sketched the famous golden rebus on the front of the tower: Lead, God, the right teachings and justice into the heart of King Christian IV.

To get to the top, one needs to walk up the spiral ramp, which is 268,5 meters long at the outer wall and only 85,5 meters long closest to the core of the building. The core is hollow, and you can step inside one of the open niches and stand on a glass floor, hovering 25 meters above the ground. The glass is more than 50 mm thick and can carry up to 900 kg per square meter.

Halfway up the tower you will find the old library hall, that once housed the entire book collection of the university, but has been a venue for exhibitions, concerts and cultural events since its reopening in 1987.

At the very top you'll find the platform with a great 360 degree city view centred by the observatory, which is still used in the winter months and is thus the oldest functioning observatory in Europe.

Opening Hours

01.10.2023 - 31.03.2024:
Monday: 10:00 - 18:00
Tuesday: 10:00 - 21:00
Wednesday: 10:00 - 21:00
Thursday: 10:00 - 18:00
Friday: 10:00 - 18:00
Saturday: 10:00 - 18:00
Sunday: 10:00 - 18:00


Købmagergade 52A

1150 København K