The Church St. John the Babtist is one of the most preserved churches from the Middle Ages in Nessebar. It was built in 10th century and the construction was made of crushed stone and mortar solder. The church is a typical representative of the transition between the shorten basilica to the cross-domed church. Architecturally, the medieval church is also three-nave and has a rectangular plan measuring 14m x 10 m. In its central part there are four pillars supporting the dome.
The entire interior of the church has been repeatedly plastered and frescoed. Some images present significant persons associated with the history of the church and the place.
The founder's portrait (from 14th century) is located on the south wall and a scene with the image of St. Marina (as from 17th century) is located on the northern face of the south-western column. Nowadays the church is used as an art gallery.