The Constamonetou Abbey lies in a picturesque location, 200 meters above sea level. It is built in a green wood, fourty-five minutes away from the coast. According to tradition it was founded by Great Constantine but was integrated by his son Constans. Another tradition states that the abbey was built by a hermit who was born in Castamona of Paflagonia. Anyway according to the historical sources, it was built in the 11th century. At the beginning of the 14th century it was burned by the Catalans but it was soon rebuilt. In 1351, Emperor John Paleologos the first defined the abbey’s land by issuing a document sealed with his golden seal. In 1360, princess Anne the Philanthropist and George Vrancovits gave many donations to the abbey. In 1393, at the third ritual of Aghion Oros it is mentioned as Constantinou abbey. Later on the abbey was burned but was renovated in 1433, by Serbia’s Commander in Chief Radits who became a monk there, under the name Romanos.
The abbey had its declining years at the end of the 16th century and it became a cenobetic abbey. In 1820, part of the abbey was built, with a donation from the wife of Ali Pasha, Basiliki. In 1853, two monks from Xenophon’s skite came to reside there and funded the abbey. In 1870, the main temple and a wing were rebuilt by contributions from Russia. Nowadays, there are five chapels in the abbey. The library which is situated over the narthex, contains 110 manuscripts, among them an erased and rewritten code of the 12th century and two illustrated gospels of the 11th century. The treasure collection contains wood from the Holy Cross, portable icons, embroidered sacerdotal vestments, objects of worship, several documents e.t.c.