The most recognisable landmark of the mountain range is the Rila Monastery, Bulgaria's largest and most important monastery, founded in the 10th century by Saint John of Rila. Due to its outstanding cultural and spiritual value it was declared a UNESCO World Heritage Site in 1983. Rila is also a popular destination for hiking, winter sports and spa tourism, hosting the nation's oldest ski resort Borovets, as well as numerous hiking trails. Some of the most important hydro power stations in Bulgaria are situated in the eastern part of the mountain range.