The church of Saint John the Theologian (Agios Ioannis Theologos) is located in the ruined settlement of Lakki, in the periphery of the village Kroustas. The temple was built on a pre-existing building, and nearby are traces of buildings from the Lakkos settlement, two threshing floors and a cistern.
Inside it has an interesting stone iconostasis (templon) which looks like it comes from the wall of the first temple. Its walls are adorned with high-quality frescoes from the mid-14th century. The western wall preserves inscriptions for the painting and reconstruction of the temple in 1348.
The frescoes include scenes from the Evangelical cycle and the Christological cycle. At the apse of the arch we see Deesis and Christ, while on the upper part of the iconostasis the are depictions of subjects commonly represented in the upper zones of the arch (Birth of the Virgin Mary, Prophet David and Solomon). From the life of Jesus there are scenes of the Ascension, the Nativity, the Stone, the Baptism and the Crucifixion. Interesting are the scenes of the Second Coming with the rare representation of the Worm and the punishments of the sinners.