N 42°39.54902', E 27°44.16979'
The Church St. Sofia, known as The Old Bishopric, is situated on the place supposed to be the old Centrum of the settlement. It is built in 5th C. AD and is a three-nave basilica with a semi-circular apse, a three-part narthex and an atrium (an inner yard of 20m width and 26m length). In the Middle Ages it served as a cathedral of the bishop with its residence in Nessebar. In 1257 it was looted by the Venetians, and many religious relics were taken to the church of San Salvatore in Venice. At the end of the 14th and the beginning of the 15th century, Mataisa Kantakuzina-Palaeologus was buried in St. Sophia, and the inscription on her tombstone is still preserved. The Church of St Sofia was used until the end of 17th C. and after that it was abandoned.