Located on the site of a Romanesque church dating back to the 10th century, this Baroque church (Kostel Sv. Vavřince na Petříně) was restored in the mid-1700s. This restoration project has formed the basis of the church that can be seen today and was designed in all probability by Kilian Ignaz Dienzenhofer and built by Ignazio Palliardi and his nephew of the same name. The dominant features of the church are undoubtedly the three towers, with the side towers standing at 24.5 meters and the central tower measuring 22.7 meters high.
There are a number of different sights within the church that people from around the region regularly come to see, such as the sculpture of St. Lawrence by J. Lederer and the altarpiece, which is painted by J.C. Monnoto and shows the Martyrdom of St. Lawrence. Although closed between 1784 and 1840, the church has been re-consecrated since the middle of the 1800s.
Since 1994 the church has been leased to the Old Catholic Church and in 1995 it was raised to the position of cathedral.