St John the Baptist is the first church one encounters on the modern paved road. Together with the church of Agioi Theodoroi and the Basilica, these are the three standing churches in the lower part of the fortified part of the castle. In the lower city, which was more extensive and populous than the upper parts, is where most of the churches of Servia are still visible.

The church of St John the Baptist is a small single-space church (internal dimensions: 4,40 x 2,65 m) with a gable roof, which takes advantage of the natural rock for the foundation of its southern side. On the eastern side of the church – the only part of the building with brick ornamentation – the semi-circular arch of the sanctuary is prominent. At the same time, to the west, a narthex was added at a later date, which was subsequently enlarged in size. The church has undergone extensive additions and alterations, mainly to the roofing on the east side and the narthex, aimed at expanding the church and improving its lighting. Despite its numerous alterations that have distorted its original form, the church should be dated to the 14th century based on its morphological characteristics.

The church’s interior was fully wall-painted, but the foundations of the church’s south wall on the rock of the ground created a severe moisture problem on the painted surfaces, as one side of the church is practically nested in the hill. The church remained without a roof for an extended period until about the middle of the 20th century, and its interior was exposed to the weather, devastatingly affecting the church’s wall paintings. Today, few traces of this painted decoration remain in the niche of the sanctuary. However, Professor Andreas Xygopoulos, before 1957, had managed to photograph and reconstruct a significant part of the iconographic program of the church, which, according to him, was applied in three successive zones (one with saints in medallions, one with evangelical scenes, and one with full-length saints). The arrangement of the iconographic program, as described by Xygopoulos, shows many similarities with the Basilica of Servia and the neighboring church of Agioi Theodoroi. The stylistic characteristics of the surviving parts of the church’s wall paintings indicate a dating to the end of the 14th century.