On a slope of a hill in Hymettus, beneath its northern summit, lies the Monastery of Hagios Ioannis Kynigos of the Philosophers, in a position that has a view over the Athens and Mesogeia plain. The katholicon of the monastery belongs to the cross-in-square, two-columned churches and it was dated to the second quarter of the 12th century by Á.Megaw. However, according to latest scientific facts, Professor Bouras has dated it to the beginnings of the 13th century. We can get information on the monastery from certain inscriptions. The first one is a tombstone of 1235, where monk Loukas and Philosophos are mentioned. The second one is a votive inscription, from which we find out that the monastery was dedicated to Hagios Ioannis Prodromos. The third one is an inscription in cornice with the date 1205, which must have been incorporated into the building during its construction. The monk Philosophos is also mentioned here. Apparently, monk Philosophos, who came from the Monastery of Philosophers in Arkadia, was its founder after he had settled in Athens. The Monastery of Hymettus was dedicated to Hagios Ioannis Prodromos, following the pattern of the Arcadian monastery.
Nowadays, from the old monastery are preserved the portal of the entrance in the west side of the monastery as well as the katholikon with more recent annexes in the west and in the south (the narthex in the west was added in the 17th century, while the open arch-shaped portico in the south is even more recent, probably of the 18th century). The masonry consists of rubble stones (rubble masonry) and cloisonne; porous stones – in certain parts walled with spolia deriving from older buildings. Great interest presents the fact that many marble architectural fragments of different periods exist around the katholikon. Moreover, in the courtyard in the south of the open arch-shaped portico and inside a fenced area is preserved the colonette with the “arai”, that is the curses against whoever would dare to pillage the monastery embezzling its property (vineyards etc.). Both the posterior narthex and the katholikon preserve wall paintings of a later date, that is of the 17th, 18th and 19th century. However, there are older painted layers in the main church and in the sanctuary, portraying mostly parts of clothing dated to the Byzantine period. The monastery is mentioned in the epistles of Michael Choniates, who used to correspond with the abbot. Nowadays, it functions as a convent.