The church of St. John the Baptist was erected in the mid-fourteenth century by the Order of the Holy Sepulchre. The previous temple in this place could have been destroyed during the devastation of the city by the Teutonic Knights in 1331, due to its location outside the line of fortifications. The construction of the nave was probably completed only around 1370, and the tower only in the fifteenth century. A small reconstruction of the church was carried out at the end of the 17th century. Then the windows in the chancel were pierced and the gothic polychrome was plastered. The interior was restored in the middle of the next century. During conservation works in the years 1902-16, medieval paintings in the chancel were unveiled.
Church of St. John is a gothic, orientated, one-nave building made of brick in flemish bond. Its chancel is slightly older than the nave and originally had only three windows. The nave is slightly taller and wider than the chancel, four-span, from the west with a four-sided tower, where the sacristy is located in the ground floor. The tower is four-storey, decorated with windows and pointed and round blendes. Outside the church is clasped with buttresses, between which there are ogival windows. From the south in the nave there is a gothic pointed portal. The nave and the chancel were covered with gable roofs.
While the church from the outside looks rather modest, its interior belongs to the most unusual in Poland. The chancel is covered with a rib vault, separated by a massive arch bands. Two deep niches were left in each of the walls, of which the west were filled with three arcades, and the east was closed with lancets. The niches were the seats of the celebrant and his assistants. The one-space nave consists of four spans and is covered with a rib vault. These ribs were hung with effective brackets with sculptural decoration. All along the ribs, five-petal roses were placed in the ranks, and in the bosses of the ribs, fantastic masks and suspended canopies.
The monastery adjoining the church was built as a stone structure, free standing in the second half of the 13th century. It was a gothic style building with a basement, probably a two-storey. Over the next years, rebuilt and expanded, it has now lost its original appearance.
Architektura gotycka w Polsce, red. T. Mroczko i M. Arszyński, Warszawa 1995.
Walczak M., Kościoły gotyckie w Polsce, Kraków 2015.