A massive Gothic brick cathedral on the southeast edge of the old town, begun in the fourteenth century and elevated to co-cathedral of the Archdiocese of Warmia in 1992. The five-aisled interior — a peculiar layout for a building of this size — is roofed with a fine net vault that has survived intact since 1596.
The baroque organ is one of the larger instruments in this part of Poland and recitals are regular through summer. Climb the tower if it is open: the view across the red roofs of the old town to the castle is the postcard shot.