Several archbishops of Mainz, a neighbouring city that was later officially divided from Höchst, used the city to their advantage in different ways. Archbishop Otgar von Mainz authorized a church, St. Justinius, to be erected around 830. St. Justin’s is now the oldest building still standing in Frankfurt, and the oldest church in the state of Hesse. Originally built in Carolinian times, its columns and roof are of particular importance and it is well-known by lovers of organ music as its original piping system gives it a very special sound, with concerts taking place throughout the year.