Rundetaarn Museum

Address: Købmagergade 52A, 1150 København (Copenhagen), Denmark

Website: https://rundetaarn.dk/en/

Hours: Daily 10am-6pm

Admission: DKK 40 (adult)

Rundetaarn (the Round Tower) is a 17th-century astronomical observatory tower in central Copenhagen built under King Christian IV as part of the Trinitatis Complex. Construction was completed in 1642 and the tower is noted for its uninterrupted spiral ramp leading to the summit.

The tower contains an observatory platform, a seventeenth-century library hall and exhibition spaces; the viewing platform provides compact panoramas over the historic city centre. The corkscrew ramp was built wide enough to allow riders and carts access in the original design and remains a distinctive architectural feature.

Rundetaarn was constructed to house university astronomical instruments and the university library and has retained its scientific and cultural functions through the centuries. It is one of the best-preserved examples of early modern observatory architecture in Northern Europe.

Located on Købmagergade in Copenhagen’s old town, the tower stands within walking distance of main shopping streets and Nørreport Station, in the dense urban core.

• Unique spiral ramp: The internal spiral ramp rises to the top instead of stairs, allowing a gentle walk to the summit; the ramp was designed for horse-drawn carriages in the 17th century.

What to See#

• Observatory and viewing platform: The observatory at the top of the tower remains accessible to visitors and offers a compact viewing platform above the city centre.
• Library Hall (Trinitatis): The library hall beneath the tower is a historic vaulted room originally built as part of the Trinitatis Complex and often used for concerts and exhibitions.

Rundetaarn (the Round Tower) is in central Copenhagen. The quickest public-transit access is Nørreport station (S-train and Metro M1/M2); it’s a 4-6 minute walk (about 300-400 m) down Fiolstræde/Købmagergade to the tower. From Copenhagen Central Station it’s a 10-12 minute walk.

Driving is rarely necessary; the tower is on Købmagergade in the old city centre and best reached on foot from nearby transit stops.

• Go right at opening or an hour before closing for the clearest views and far fewer people on the observation platform; the best light for photos is late afternoon.
• Use the gentle spiral ramp-there are no steep stairs-so you can take a slower pace to enjoy the astronomical exhibits and the library hall along the climb.
• Don't miss the small rotating exhibitions and the view back down into Trinitatis Church from the gallery level; these interior details are often overlooked by visitors focused only on the top viewpoint.