The Church of "Holy Saviour"or "St. Spas" is a small single nave and single apse building, 11,70m long and 5,70m wide located in the Northern part of Nesebar. It was built in 1609 by donations of a rich resident of Nesebar during the time of Bishop Cyprian. This is visible from the label for charity placed above the south entrance. In the past a narrow and long narthex passed through the whole northern part and thus the width of the church was 9.80 m. The years of yoke leaded to the need of fast construction and the wooden roof with eaves is without edging. The eastern facade was half dug in the ground. During archaeological excavations in 2012-2013, it was discovered that the church was built on the foundations of an Early Byzantine three-nave basilica, dating from the 6th century. In its original plan, the basilica had one apse, semicircular inside and outside. Subsequently, two more semicircular small apses were added, one to the north nave and another one to the south nave.  The church is wallpainted by a anonimous painter in the beginning of 17th century. The wall paintings represent scenes from the life of Christ and Holly Virgin. The Virgin Platytera is painted in the apse. 

The tombstone of a Byzantine princess Mataissa Cantacuzina was saved in the church a long time. Now the gravestone is in the Archaeological museum of Nessebar.

The walls inside are covered with frescoes, which are among the best examples in our country of temple paintings in the period 16th - 17th centuries. In the apses are the paintings of "the Virgin and the child"; a young saint with a robes of a great bishop and with a gospel in his hand. There are several paintings of saints visible on the walls and the painting on the right of the apse are completely destroyed. On the south wall the frescoes are almost destroyed. On the rest of the wall the frescoes are divided into two belts. In the upper belt are presented evangelical scenes. The lower belt includes compositions with images of whole figures of saints. The western wall was later rebuilt of stone and mud, and if there were frescoes on it, they are now missing.

The frescoes on the north wall are divided in two rows. In the upper rows scenes are presented and three medallions are painted in the altar part. In the down row are paintings of saints.Three medallions can be seen in the altar, and below them is the scene of St. Peter of Alexandria with Christ.
Nowadays the church is a museum.