Geologically, the Treskavica range is part of the Dinaric Alps and formed largely of secondary and tertiary sedimentary rock, mostly limestone and dolomite. A number of beautiful mountain lakes are scattered throughout the group, of which Veliko Jezero is the largest. A number of streams source from these mountains: the Bistrica tributary of the Drina river, the Željeznica tributary of the Bosna river, Ljuta and Rakitnica tributaries of the Neretva. Notable peaks are Mala Ćaba (2088 m.), Pašina Planina (2070 m.), Mali Treskač (1950 m.) and Lupoč (1773 m.).