At position Katsivelos in Ancient Eleftherna the archaeologists have revealed the ruins of an imposing basilica. The basilica was built on the site of an older temple of the 3rd century BC, probably dedicated to Hermes and Aphrodite. The basilica was founded by the Bishop of Eleftherna Efratas around 450AD and was dedicated to the Archangel Michael.
It was three-aisled, with pillars supporting the arches between the naves, and the interior bore colorful tiles in geometric and plant formations. The floor of the nave was paved with rectangular plates, while the floor of the sanctuary still retains part of a colorful marble cover in strict composition. The rest floors were adorned floral and geometric mosaics.
At the south side of the basilica tombs of the 7th century AD were found. Opposite the western entrance of the church a building of the 5th century was possibly the residence of bishops.