In the Middle Ages, Lübeck had become a wealthy city. In order to protect itself from its enemies, Lübeck built three city gates. Two of them remain and the Holstentor is one of them.
The gate dates from the 15th century. During the centuries afterwards, the Holstentor underwent various stages of demolition and restoration. Nowadays, it consists of a north tower, south tower and a central building, all with 4 floors. There is a museum inside the gate, dedicated to the history of Lübeck.
You can find the brick Gothic construction at the western side of the old city center.