Karlstor in Munich (called Neuhauser Tor until 1791) is one of what used to be Munich's famed city wall from the medieval ages till late into the 18th century. It served as a major defensive fortification and checkpoint.
It is located at the western end of Neuhauser Straße, a portion of Munich's down-town pedestrian zone, which was part of the salt road and the east-west thoroughfare of the historic old town. Thus it separates the historic centre from a 19th-century extension called Ludwigvorstadt (Vorstadt meaning 'suburb'). Karlstor receives its name from Karlsplatz (better known under its local nickname "Stachus"), which is now part of the Altstadtring circular road and has been one of the busiest points of Munich for centuries.
The building is the westernmost of three remaining gothic town gates out of originally five. The other two are Isartor in the east (the only one that is still complete in its basic structure) and Sendlinger Tor in the south-west. Missing nowadays, after the whole fortification system had to be laid down on prince-electoral order at the turn from the 18th to the 19th century, are Angertor in the south and Schwabinger Tor in the north, as well as all "minor" or side gates and the entire double walls.(Wikipedia)
"Munchen - Karlstor"