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 which is now part of the Altstadtring circular road and has been one of the busiest points of Munich for centuries.