The Cathedral Basilica of the Nativity of the Blessed Virgin Mary is a Gothic structure from the 1360s, built under Casimir the Great on the site of an earlier Romanesque church. The exterior is relatively plain, but the interior contains one of Poland's most unusual sets of church paintings.
The Ruthenian-Byzantine frescoes in the chapels date from 1708 and cover the walls with scenes of Old and New Testament figures rendered in an Eastern European iconographic style. The effect is striking — the warm, slightly flattened faces and the rich ochres and blues of the Byzantine palette give the interior a distinctly non-Western character. The crypt below the nave contains the remains of several bishops and town notables. Sandomierz Cathedral is a diocesan seat and remains an active place of worship.