The Monastery of Agios Nikolaos of Sintza is located in a rocky, hard to reach area to the south of the Leonidio valley, at a distance of 6km from it. It is built inside of a cave, and its reforming into sketes was done in the later 16^th century AD. The monastery's foundations are built on solid ground, due to the utilization of the openings in the rock, and to the east of it, visitors can see the shallow caves of the hermitages. Higher up, two wings of structures have been built (cells and guest houses) and in the central part, the katholikon, which was built according to the cross-in-square or crossed-dome plan. Its dome has eight sides. The main entrance is located on its south side. In the interior of the temple, visitors can see traces of murals, as well as the icon of Agios Nikolaos (Saint Nikolaos), which dates back to 1767, and depicts a rare theme, the Assumption of the Saint. There is a small chapel built next to the monastery, dedicated to Agios Dionysios (Saint Dionysios) where the lore claims the icon of Agios Nikolaos was found.

The inside of the cave was used for auxiliary and storage spaces alike. During the times of both the Turkish Rule and the German Rule over the Greek people, the monastery served as a place of refuge for the Greek soldiers. The construction of the monastery is dated to sometime between 1200 and 1300. It is a fact that the monastery was mentioned in a document of the patriarchy in 1622, and that it was renovated in 1783, as is evident by an engraving made on the transom of its entrance. The dominant theory about the origins of its name, Sitza or Sintza, is that it comes from the word "sykia" (meaning "fig tree"). The cave of Sintza was inhabited for the first time during the ealry Neolithic Age, which has been proven by the discovery of fragments of pots, cups, kraters (a kind of urn), and silver daggers within the cave's interior.

The monastery houses a library with hand-written Gospels and old editions of texts. It was also the keeping place of the holy remains of the saints Nikolaos, Trifon, Paraskevi, Panteleimon, and Dionisios for some time. The icons that are exhibited around the rooms of the monastery are dated back to the 16^th and 17^th century. To the outside of the building complex of the coven, there is a water spring, and a roman tomb carved onto the rock beside that. It was changed from a men's monastery to that of women in 1953. The monastery celebrates Agios Nikolaos on the 8^th and 9^th of May of every year, as well as Agios dionysios every 3rd of October.

Source: Holy Cathedral of Mantineia and Cynouria. T. Vagienas. The monasteries of Arcadia. Greek Monasteries.