The Koppelpoort is a unique combination of a land gate and a water gate, the only one in the Netherlands. The name Koppelpoort refers to the area outside the gate called De Koppel. The Koppelpoort dates from 1425 and is part of the second city wall. The area between the first and second city walls served as common pasture for the farms that had come to lie within the walls. The gate is located on the northwest side of the city center, where the canal system leaves the city center. The water flows from the city into the Eem.