The monastery of Agios Ioannis Theologos dominates the hill above Hora and is visible from every part of the island. It was established in 1088 by St Christodoulos after the donation of Alexios Komnenos A'. It has been, ever since, the most significant religious and cultural center on the island. The chapel of Agioi Apostoli, where the relic of St Chistodoulos is kept, was built in 1603. The exterior of the monastery is surrounded by tall, thick walls with fortifying towers and ramparts, built according to the Byzantine style with rectangular, while stone stairs leading to an impressive gate. The yard has layers of pebbles and is beautifully decorated. In the center, there is a water-tank and a well with holy water. The eastern side is dominated by an arch with four curves and many frescoes representing the miracles performed by Agios Ioannis Theologos. The monastery houses ten chapels, the Chamber where the monks hold their meetings along with the cells of the monks. The most impressive part of the monastery is the church. Inside one can admire the beautiful wood-carved icon stand, the marble floor and the rich decoration. The Library, established by St Christodoulos, is of extreme interest, as it includes 2,000 volumes, 13,000 historic documents and 900 manuscripts. Among these, one can see 30 manuscripts bequeathed to the monastery by Chirstodoulos's successor, Savens, the collection of Nikiforos Laodikias, works of ecclesiastic father codes, biographies of Saints and Aristoteles's Accusations. In the treasury of the monastery, the monks keep invaluable objects, remarkable icons, ecclesiastic utensils and garments.