Brandenburg Gate

The Brandenburg Gate on the Luisenplatz in Potsdam, not to be confused with the gate of the same name on Berlin's Pariser Platz, was built in 1770–71 by Carl von Gontard and Georg Christian Unger by order of Frederick II of Prussia. It stands at the western end of Brandenburger Straße, which runs in a straight line up to the Church of St. Peter and St. Paul.

Previously, from 1733, there was another, simpler gate on the same spot, which resembled a castle gateway. Together with the city wall, a form of toll or excise barrier, and the other gates it was intended to prevent desertion and smuggling.

Source: Wikipedia