Skantzoura is an 8 km2 large and flat island with hills and with large parts of its shores made of white marble. It is situated at about 20 kilometer distance south / southeast of the island of Alonissos and 30 kilometer northwest of the island of Skyros. The vegetation on Skantzoura is quite low with shrubs but there is also a forest with low cedar trees and there are olive groves. Skantzoura used to be a monastic island, but the Monastery of Evangelistria which is situated in the middle of the island is now closed. On the island live and breed rare species of birds like the Audouin's Gull and Eleonora's falcon.
The rare monk seal also inhabits the island. The island is situated in a part of the marine park prohibited for boats and visitors to aproach or visit. On the island there are also no sheltered bays for boats to moor.
Since 2011 there are no longer people living on the island.
The monastery on Skantzoura is old and interesting with a church, and several outbuildings, stables and storage rooms.
Just like the monastery at nearby Kyra Panagya it belongs also to monastery of Agia Lavra on Mount Athos on the mainland.
Behind the monastery are terraces which were the former vineyards. Near the coast are the ruins of an even older monastery, the first monastery that was built on the island.