This Romanesque tower, also known as the Donjon, is the oldest structure at the Castle Hill and in Lublin. The tower was erected in the second half of the XIII century. It is about 30 meters high, and the thickness of its walls reaches even 4 meters at ground level. The lower part of the tower is made out of limestone, and the upper part out of bricks.

The spiral staircase within the walls leads to three floors. A characteristic feature of Romanesque style, known as a biforium, is a pairing of two arcade openings separated by a colonette which lets sunlight into the top floor of the tower.

For some time the tower combined residential and defense purposes. In XVI century it served as a prison for the nobility. It had a similar function in XX century, as during the II World War a gestapo prison was located at the castle, and between 1944 and 1954 as a political prison of the NKWD and national security office.

Currently the tower houses historical exhibitions, and on its top there is a viewing terrace on the top of the tower, which offers a spectacular panorama of the Old Town and the city. The tickets are available at the museum's ticket office or from the ticket machine at the castle courtyard.