One of the oldest of Munich's city gates was built in 1337 and served as a fortification for the defense of the city under Kaiser Ludwig of Bavaria. It is the only gate to remain in its original form and is one of the few remaining landmarks from that period. The Isartor was restored between 1833-35 by Friedrich von Gärtner. The frescoes, painted in 1835, depict the victorious return of Kaiser Ludwig after the Battle of Ampfing in 1322. The building now houses the Valentin Musäum.