The Monastery of Agios Ioannis (Saint John) Siderianos is located on the western part of Milos island. It can be reached through a track road from the center of the island and only a few monks live there today. The surrounding area is almost deserted, as there is no village nearby.
According to the locals, this monastery was the sight of a miracle: in the Medieval Times, some locals had locked themselves inside this monastery to protect themselves from pirate attacks. They prayed to Saint John and that time the wooden door turned into iron, which is how the monastery took its name (Siderianos in Greek means iron.)