Metzgerturm Ulm

The Butcher Tower in Ulm is a city gate of the medieval city fortification on the Danube that is still preserved today. The square brick tower with pointed arch gates was built around 1340 as the outlet of the Stauf town fortifications to the town butcher in front, the town's slaughterhouse. The upper floor with cantilevered arch is completed by a steep hipped roof.

(Https://de.m.wikipedia.org/wiki/Metzgerturm_(Ulm))

According to a legend, the tower was named after Ulmer butchers, who were locked up in the tower because they stretched sausage with sawdust.

The Butcher's Tower was not a city gate. In 1480, the city wall was rebuilt and moved towards the Danube, which meant that the Butcher's Tower was set back. The breakthrough through this wall only happened in 1930.
The Butcher's Tower was built around 1349 and is 36.1 m high. The foundation facing the Danube was based on the old city wall, but facing the city on wooden logs that eventually rotted as a result of the lowering of the Danube water level. In 1911, concrete foundations were put in. Since then, the inclination to the west has slowed down considerably. It is currently 2.05 meters.
You can find more information and the story of the butchers here: tourismus.ulm.de/de/entdecken/sehen-und-erleben/sehenswuerdigkeiten/historisches/metzgerturm-ulm