The monastery was founded in the first half of the 11th century by a man from Kastamoni in Anatolia, from whom it takes its name. A more recent benefactor was the Christian wife of Ali Pasha,… Vassiliki, who largely financed the restoration of the monastery in 1819-1820. The katholikon, dedicated to St Stephen the Proto-Martyr, was built in 1867, and is the fourth church on this site. The most important treasures are the three miraculous icons of St Stephan, the Virgin-who-Guides (Hodegetria) and the Virgin-who-Answers (Antiphonetria).
It is distinctive in the Holy Mountain because it is one of the few monasteries which isn’t close to sea.