The Church of Panagia Platsani is among the largest in Oia. It is also fairly new. It was built in the late 1950s to replace a much older church within the walls of the Venetian castle of Oia that collapsed during a powerful earthquake in 1956. The name Platsani comes from the Greek word for the sound of waves (plats) and refers to the miraculous discovery of the icon of the Virgin Mary at sea.