The Zijlpoort (literally "Zijl Gate") is, along with the Morspoort, the only one of the eight former city gates to have survived. The gate was built in 1667 in the neoclassical style according to a design by the Leiden architect Willem van der Helm and adorned with sculptures by Rombout Verhulst. The clock was cast by Hemony in 1668. Since the gate had to be connected to both the former city wall and the bridge in front of it, the building is shaped like a parallelogram. The Oude Rijn flows from the nearby River Zijl through the Zijlpoort into the city of Leiden. The Oude Zijlpoort, the predecessor of this gate, was located 300 meters further west on Haarlemmerstraat (between Koestraat and Havenplein), where the old city wall originally ran.
Over time, the Zijlpoort, and especially the hall above the passage, served various purposes: in the early 18th century, rhetoricians met here; from 1736 onward, a school for poor children was established there; and in the 19th century, municipal goods were stored there. In the last quarter of the 20th century, the Zijlpoort underwent two major renovations. During the most recent renovation in the 1990s, supporting structures were added to both sides of the gate. Since 1999, one of these structures has housed a restaurant. The cemetery of the same name has been located next to the Zijlpoort since 1828. The gate has been a national monument since 1968.
(Source: Wikipedia)