The Round Tower is a 35-meter-high circular building with unique architecture. A broad spiral ramp, known as the Spiral Walkway (Sneglegangen), winds from the entrance on Købmagergade up to the stairs leading to the tower's top. The Spiral Walkway wraps around the tower's hollow core 7½ times and is the only access to the top, where visitors can experience the Library Hall, the Bell Loft, and the hollow core. It is precisely the Spiral Walkway that makes the Round Tower one of Denmark's most iconic buildings.
The tower was originally built as an astronomical observatory to assist astronomers in studying the movements of stars and planets. It also played an important role for the University of Copenhagen as a library where students could access books and manuscripts.
Today, the Round Tower is a popular tourist destination where visitors can enjoy a fantastic view of Copenhagen. From the tower's top, there is a panoramic view over the city, making it a favourite spot for photographing Copenhagen's skyline.