Rila Monastery, officially the Monastery of Saint Ivan of Rila, is an Orthodox monastery in Bulgaria. Founded in the 10th century, it is the most important and largest monastery in the country. The complex is a UNESCO World Heritage Site and considered a symbol of Bulgarian culture. It is located in the Rila Mountains at an altitude of approximately 1,147 meters above sea level.

http://whc.unesco.org/en/list/216