One of the most popular and spectacular beaches in Alonissos. The sea looks white with coarse and fine pebbles. The unique characteristic of this beach is its horse shoe shape and for this reason, the water deepens rather suddenly. The name is owed to the monastery of St. Demetrius, which once existed in the area, which was destroyed by pirates, the remains of which can be found at the top of the beach. Just above the beach, there is a lake created by the rain and wetland for migratory birds. In summer, however due to the heat the water is evaporated. The beach is organized with umbrellas and sun beds as well as restaurants and canteens. Due to its length, there is plenty of space even in August.