The Round Tower
In the heart of Copenhagen lies the Round Tower – one of Denmark’s most iconic buildings. In addition to its characteristic spiral staircase leading up to a spectacular 360-degree view of the city, the tower also hosts exhibitions, concerts, events and Europe’s oldest functioning.
The Round Tower was built in 1642 by Denmark’s most industrious king, Christian IV. The foundation stone was laid on 7 July 1637, and five years later the tower was completed as the first part of the Trinitatis complex, which was intended to house three things: The observatory at the top of the tower, the University Library on the floor above Trinitatis Church and the church itself below.
King Christian himself sketched the famous golden rebus on the facade of the tower, which translates as: ‘Guide, God, the right doctrine and justice into the heart of King Christian IV.
Culture all year round in the Library Hall
Halfway up the tower – somewhere between the cobblestones and the stars – is the Library Hall. Here you can experience changing exhibitions all year round, ranging from arts and crafts to science and history. The beautiful, bright hall also hosts a wide programme of concerts, talks, tours and activities for both children and adults, as well as the Round Tower shop and café where you can enjoy a cup of coffee and find books, posters and other fine items to take home.
Information
Opening hours
Winter Season
24 November – 31 March
Open daily 10 AM – 6 PM*
Additional closure days due to restoration:
• From 24 November: The Observatory is closed until the restoration is completed.
• 8–12 December: The viewing platform will be closed.
• 5 January – 5 February: The entire Rundetaarn will be closed.
Regular closure days:
24 and 25 December, as well as 1 January.
On 31 December, Rundetaarn closes at 3 PM.
Summer Season
1 April – 30 September
Open daily 10 AM – 8 PM*
Expect closure days at the end of April – dates to be announced.
Admission
Adults: 60 DKK
Students: 40 DKK
Children (0 – 17 years): 0 DKK
Prices are subject to change. Please visit the museum’s website for more information.
The Round Tower’s Observatory to be restored in 2025/2026
In 2026, the nearly 100-year-old observatory building will undergo restoration to preserve this important piece of cultural heritage. The copper roof of the dome is worn, and the purpose of the project is to future-proof both the Observatory and the tower itself, ensuring that Christian IV’s historic “star castle” can continue to be experienced by generations to come. The dome will be restored at a temporary construction site at the base of the tower, where visitors will occasionally be able to follow the process. The Observatory beneath will also be refurbished — the floor will be renewed, and the old refracting telescope will be restored by a specialist in Germany.
During the restoration, there will be changes in accessibility. Apart from the announced closing days, the tower will remain as open as possible throughout the process, giving visitors the opportunity to follow the restoration from street level and get close to the preservation of cultural heritage, history, and craftsmanship.
The public observatory is expected to reopen in autumn 2026.
Find Questions & Answers about the visitor experience at https://www.rundetaarn.dk/en/article/visitors-and-neighbours/
The fabled Spiral Ramp
The Spiral Ramp in the Round Tower runs from the entrance in the street of Købmagergade to the stairs leading to the top of the tower. It winds 7½ times around the tower’s hollow core and is the only way to the top. The Spiral Ramp is the main thoroughfare of the Round Tower, giving access to both the Library Hall, the Bell Loft and the hollow core.