It is an old male monastery dedicated to John the Baptist. It is located in the gorge of the river Tanos near the village of Perdikovrysi in Kastri and is built on a steep rock. The landscape surrounding the monastery is imposing and with its unspoilt natural beauty.
An inscription testifies to the historical presence of the monastery since 1126. Other inscriptions also testify that it was renovated in the 18th century. Based on these and other existing written testimonies, the monastery is considered to be the oldest monastery in the Peloponnese.
The history of the monastery is very rich. Because of its inaccessible location, it was used during the struggle of 21 as a stronghold against Ibrahim and as a refuge during his raids. In fact, his watermill milled gunpowder for the needs of the race. It is the only monastery that withstood the siege by the troops of Ibrahim who besieged it twice without success (there are several related reports from Makrigiannis and others). In fact, the monastery allocated a large part of its property to rebuild many of the destroyed monasteries of Arcadia.
The monastery still operates today and celebrates on August 29.
Source: UNIVERSITY OF PATRAS