Set against the shimmering azure of the glittering Aegean Sea, the Santorini Blue Domes feature in almost every single postcard from the quintessential Cycladic island. The most photographed Santorini blue domes churches are located in Oia and are the churches of Agios Spiridonas (Saint Spyridon) and Anastaseos (the Church of the Resurrection). Both are built at the edge of the cliffs right next to one another.
While still wandering the streets of Oia, you may also want to visit another Santorini blue domes church, Panagia Platsani, which is dedicated to the Akathist Hymn of the Virgin Mary. Originally, it was built inside the castle of Oia, but a destructive earthquake in 1956 made the soil extremely unstable and ruined the church. It was rebuilt, though, at the center of Oia, where it stands to date. It now hosts all the major annual celebrations in its beautiful front courtyard.source:antoperla.com