The baroque church was built in 1703-1756. The cupola has 75 meters, reminds one of St. Peter’s Cathedral in Rome. Nicolas was the patron of sailors and merchants. The builder of the church was K. I. Dientzenhofer. Its rich sculptural decoration originated in the Antonín Braun's workshop, and the interior frescos were painted by Kosma Damian Asam. Originally the church belonged to the Benediktine order, nowadays it is used as the main church of the Czechoslovak Hussite Church.