The zones of the Rila mountain range that fall within the park are formed mainly by metamorphic rocks - gneiss, biotite gneiss, amphibolite, mica, schist and marble, bordering to the north and to the east with coarse-grained granite, granite-gneiss, smooth-grained granite and pegmatite veins [REF].
The average altitude of the park is 1750 m and the highest summit is Rilets at 2713 m [REF].