Altarpiece in a single section by an unknown artist; tempera on pine wood with stippling reliefs. It attests the moment of transition between the end of linear Gothic and the arrival of Italianism around 1350. The middle compartments are dedicated to the titular saints, St John the Baptist and St Margaret of Antioch. Presiding over the altarpiece is a Calvary. On the left there are three episodes from the life of St John and on the right another three from the life of St Margaret.