The canyons cut vertically into the mountain interrupting the continuity of the slope, which stretches down to the shore. They are also the most powerful forms of erosion on the whole of Velebit forming cliffs some 300-400 metres high. Vaganski vrh, Babin vrh, Segestin, Malovan and Sveto brdo. The park covers the Velika Paklenica drainage system, including the tributary Brezimenja a and the stream from Suha Draga, and the Mala Paklenica area with its tributary the Orlja a. Due to the porous rock of Jurassic and Cretaceous limestone and Paleogene limestone and breccias the beds of the Velika Paklenica and Mala Paklenica are dry almost throughout the whole year.
Water fills the beds only during heavy rainfall and when the snows melt in the Spring.
Today, the Manita pe rises high above the Velika Paklenica valley bed, however, one of its underground streams once ran through the grotto. As the Velika Paklenica cut into its valley the grotto remained dry and was slowly filled with an imaginative dominion of stalagmites and stalactites. The National Park is not very large, but extends over a wide range of altitudes from 20 to 1,660 metres. Two-thirds of the park is forest, including degraded forest areas of coppice closer to the coast and in settled areas. The best-preserved forest areas are to be found in the upper valley of Velika Paklenica, which is predominantly beech.