Klek is on the north-western ridge of Velika Kapela and it is 1,181 metres high. It dominates the valley in which Ogulin lies (323 metres above sea level). With its miraculous shape and intimidating beauty Klek is known to many alpinists, mountaineers, botanists, travel writers and nature lovers. In clear weather one can see its unusual shape even from Zagreb, while the attractive surroundings which spread for a hundred kilometres around Klek, can be seen from its highest peak.
Its 200 metre high vertical rock face is the cradle of Croatian mountaineering and alpine climbing. In 1874, the idea of founding a mountaineering society here was proposed in Ogulin.
The oldest written document on climbing Klek dates from 1838, when Croatian Ban Josip Jelačić, accompanied by the Saxon King Frederick Augustus II, a well-known amateur botanist, reached the top of Klek.
Klek is one of the botanic reserves that have rich tertiary flora: Kitaibel's Primrose, Hairy Alpenrose, Maly Moon Carrot, Micromeria Croatica, Gentianae Radix, Anthyllis alpestris, Carniolan Lily, Alpine Clematis etc. Thirty kinds of orchids have also been discovered. Many protected animal species have their habitats here too: wolf, bear, lynx, grouse and wild cat.