Built in 1667 in the classical style according to a design by the Leiden architect Willem van der Helm and with sculpture by Rombout Verhulst. Because the gates have to connect with the city wall as well as with a bridge, the building is in the form of a parallelogram. Together with the Morspoort, the Zijlpoort is the only one of the original eight gates that survive. The name refers to the nearby river, the Zijl.