Rundetårn (or Rundetaarn, lit. The Round Tower) is a 17th century tower located in Copenhagen, Denmark. The tower is part of the Trinitatis complex, which was built to provide the scholars of the time with an astronomical observatory, a student church and a university library.
History
One of his most well-known buildings, Rundetårn was built upon request from King Christian IV and designed by architect Hans Steenwinckel the Younger. The foundation stone was laid on July 7, 1637, and the tower was finished in 1642. The Trinitatis church was not finished until 1656, and the library not until 1657. The observatory (which is the oldest functioning observatory in Europe) and the library were used by the University of Copenhagen until 1861. Astronomers having used the observatory include Ole Rømer (1644-1710).
Architecture
A 7.5-turn helical corridor leads to the top of the tower, where the observatory and a minor planetarium is located. The corridor also provides access to the church and the library.