Panagia Ekatontapiliani is a Byzantine sanctuary thought to have been built in the 4C by Constantine, in line with his mother's wishes. The current building dates from the 10C. The "Church of a Hundred Doors" blends a three-nave basilica floorplan and the Greek cross floorplan. Inside, the iconostasis on four 6C columns bears three remarkable 17C icons. The Agios Nikolaos Chapel, perhaps from the 4C, is closed off by a Doric colonnade. The small Byzantine Museum is housed in the cloister.