The Holy Monastery of Grigoriou was built in the 14th century toward the glory and honor of Saint Nicholas by Gregory, disciple of Saint Gregory the Sinaite.
Within the enclosure of the monastery there exists a chapel dedicated to Saint Anastasia the Roman.
The monastery was destroyed by fire in 1761. Joachim Makrigenis (lit. long-bearded; he was named such because, although his beard was sparse, by a miracle of Saint Nicholas it grew long, even to the floor), after much effort and many trips to Constantinople and Moldavia, collected enough money to rebuild the H.M. of Grigoriou.
Its library has 297 manuscripts.