The former donkey gate of the city wall gave Pfortenstraße its name. It led directly to the Margarethenhospital, founded in 1358. The area is now occupied by the Tilesius Grammar School, which was built in 1913. The medieval portal gate was demolished in 1891. To the west is the impressive Hirschgrabenwall, which was built in 1505. At the end of the 18th century, citizens built garden and pleasure houses on the formerly mighty round and shell towers of the town wall.