The Rundetaarn is a 17th-century tower located in central Copenhagen, Denmark

The Round Tower as seen from Købmagergade street.

The Round Tower as seen from Krystalgade street.

This information board is hanging at the entrance to the Round Tower.

The interior of the tower is one big walkway.

To get to the observation deck you need to walk up the spiral walk.

The tower contains a toilet which was used by the researchers and astronomers working in the tower.

The dome of the Trinitatis Church as seen from the Round Tower.

The dome of the Marble Church and the large industrial pipes of Amagerværket power station as seen from the Round Tower.

The former church of St. Nicholas as seen from the Round Tower.

Købmagergade street as seen from the Round Tower.

The Christiansborg Castle tower, The round dome of the Christiansborg Slotskirke and the Church of the Holy Ghost.

The towers of Copenhagen City Hall and Palace Hotel, the Church of Our Lady.

The Church of Our Lady as seen from the Round Tower.

St. Peter's Church as seen from the Round Tower.

The Great Synagogue as seen from the Round Tower.

St. Andrew's Church as seen from the Round Tower.

The observation deck of the Round Tower is spacious.

The Palm House of the University of Copenhagen Botanical Garden as seen from the Round Tower.

Rosenborg Castle as seen from the Round Tower.

Rosenborg Castle Gardens as seen from the Round Tower.

Amagerværket power station as seen from the Round Tower.

The Church of Our Saviour as seen from the Round Tower.

A telescope is mounted in the Round Tower's public observatory.

A sky map with constellations is on the wall.

The spiral walk of the Round Tower is 268,5 meters long at the outer wall and 85,5 meters long close to the core of the building.

The public toilet of the Round Tower is modern and comfortable.

This is the entrance to the Library Hall of the Round Tower.

The Trinitatis Church is part of the 17th century Trinitatis Complex, which includes the Rundetårn astronomical observatory tower.