The Rila monastery, located about 120 km from Sofia, is undoubtedly Bulgaria's largest and most famous monastery. Located on Mount Rila at 1.147 meters above sea level is surrounded by the small rivers Rila and Drusljavica. It was founded by Hermit St. John of Rila from 876 to 946 in the 10th century, during the reign of King Petar from 927 to 968. Saint John of Rila, whose relics are displayed in the church of the sanctuary, in fact housed in a little cave distant. It is known that the monastery was built by the disciples of John of Rila, who had gone to study him. The monastery was highly respected and had countless privileges since its construction. All Bulgarian kings, from Ivan Asen, from 1218 to 1241 often brought great gifts. The sanctuary reached its peak in the period from the XII to the XIV century. In the 14th century Bulgaria saw the arrival of Ottoman invaders; in 1378, during the reign of Ivan iman, the country fell under the Ottoman yoke and the monastery was destroyed. His rebirth began in the late 15th century. During the National Risorgimento, during the 18th and 19th centuries, the monastery was rebuilt thanks to the offerings from all over the country, donated by the most prosperous Bulgarians. Like many other monasteries, even during the Ottoman yoke, the monastery of Rila was the center of spiritual and cultural life for the Bulgarian people. The monks of the time created new works and transcribed books of historical authors, mainly from the Tarnovo school and Mount Athos. These works are still preserved in the library. In 1976 the Rila Monastery was declared a national historic monument, and in 1983 it was included in the UNESCO World Heritage List. With its high walled walls and numerous slots, the shrine, at least externally, looks more like a fortress than a monastery. The complex consists of a four-storey building with 300 cells in all, a large courtyard, a church and the tower of the Hrelio despot. The most precious work of art, contained in the church of the monastery, is the iconostasis, carved in wood. The walls were frescoed by Zahari Zograf and other painters. In the church there are many icons dating back to the 14th and 19th centuries.