Orjen is adorned with various karst forms, cracked rocks, pits and sinkholes, as well as an endemic species of Heldreich’s pine, some of which are 650 years old. Going through the rugged nature, abandoned summer pastures (katuns) and the remains of military settlements is a kind of adventure that stimulates curiosity. You can get more information about the activities on the mountain in the Mountaineering Club „Vučji zub“ Trebinje (www.vucjizub.org) and the Speleological Society “Zelena brda”.