The early Christian Basilicas at the beach of Agios Stefanos, within Kefalos bay, at a distance of 40 kilometers southeastern to the town of Kos, are dated in the 5th or 6th century, with more recent additions. They are two of them, the southern and the northern ones.

Some buildings are also preserved at the southern side of the church; one of them is arched and, according to the suggestions of scholars, it was used as a sacristy. The floors of the church are all covered with excellent mosaics, while at the parts of the walls preserved have sculpted decoration.

The Northern Basilica is also three-aisled, but of smaller size. The most characteristic feature is that the three aisles are formed from columns and pillars alternating each other. Here too, we find the semi-circular arch at the East, where a part of the throne, made up of marble is still preserved. The mainstay of the wall baring the presbytery is visible here too. The rectangular narthex of the western part is also present. Out of the church, at the East, a rectangular building (whose only the floor plan is possible to reconstruct) with the relics of a rectangular font, seems to have served as a baptistery for both churches. The atrium of this basilica is thought to have been constructed later, possibly in the 6th-7th centuries A.D.