The Hauptwache (English: Guardroom) is a central point of Frankfurt am Main, Germany and is one of the most famous plazas in the city. The original name Schillerplatz was superseded in the early 1900s. It lies to the west of Konstablerwache with both squares linked by the Zeil, the central shopping area of the city. The baroque building which gave the square its name, was built in 1730. It was the headquarters of the city's Stadtwehr militia when Frankfurt was an independent city state and also contained a prison. In the 18th century Frankfurt still had city walls and its own army. Until 1864 the place surrounding the building was called Paradeplatz reflecting its military function. Today, Hauptwache station serves as one of the most important crosspoints of the Frankfurt public transport system. Eight of nine S-Bahn lines serve the station as well as six of nine U-Bahn lines.