The Sendlinger Tor is a city gate at the southern extremity of the historic old town area of Munich. It served as a fortification for the defence and is one of Munich's three remaining gothic town gates (Sendlinger Tor, Isartor, and Karlstor). The Sendlinger Tor lies at the southern end of Sendlingerstrasse, the north-south highway through Munich's old town. Thus separates the Sendlinger Tor of the old city from the Isar suburb. As part of the great urban expansion by Ludwig the Bavarian (from 1285 to 1337), a second city wall with four town gates was built, of which Sendlinger Tor was one.