The Basilica of the Holy Mother of God Eleusa occupies a sea-facing position on the northern side of the old town. It survives as low ruins, but the setting is excellent: stone foundations, open water, and the edge of the peninsula.
It is a quieter counterpoint to the busier churches in the centre. Visit it while walking the perimeter of the old town, when the sea views and archaeological fragments make more sense together than they would on a rushed inland route.