The Park contains large meadows, over 100 peaks rising above 2,000 meters, among them the highest at the Balkans Moussala peak 2925m as well as a variety of rock faces, precipices, caves, deep canyons, and waterfalls. Its territory is dotted with about 120 lakes-70 date back from the Ice Age. Most of Rila National Park is covered in thick forests-primarily spruce, white fir, and Macedonian pine. The higher plant species identified thus far, within the park, constitute 38.35% of the higher flora of Bulgaria. The most beautiful among them-the Rila cowslip, the lady's mantle and the Rila rhubarb-are all Bulgarian or Balkan endemics (species occupying a limited geographical area). The Rila cowslip is the most common locally endemic species within the Park. The total number of species endemic to Bulgaria or the Balkans in the Park is 57 (18 of which are endemic to Bulgaria, 36 to the Balkans).
Many species of the lakeside and rocky fauna have survived since the Ice Age. These form the rather large group of glacial relicts (pre-dating the Ice Age)-105 species in the Park's territory. The Park is a haven for a whole range of rare or endangered species. Of all higher plants identified within the Park, 98 are listed in the Red Data Book of Bulgaria: 8 as endangered, and 90 as rare (making up some 13% of all listed species). Forty two plant species are protected by Bulgarian law, proof of the huge conservation significance of Rila National Park.