Located in the Kazimierz district, this is one of the city's finest Gothic churches. Modelled on the Church of Our Lady on the Rynek, it was founded in 1363 by Casimir the Great, in repentance, so it is said, for the assassination he ordered of a nun. The vicissitudes of history explain its austere and plain interior, broken only by the monumental great altar (1634), miraculously saved. Also of interest is St Monica Chapel at the end of the right-hand nave.