The Rhodopes are considered to be the oldest land on the Balkans. Their eastern part stretches between the valleys of the big rivers Arda and Maritsa. The mountain's rolling hillsides alternate with rugged landscape of jagged peaks, towering cliffs and sparsely vegetated, boulder-strewn slopes.

Exceptional biodiversity - a result of the impact of the Mediterranean and continental climate - is concentrated in a small area. The diversity of birds of prey is amazing - 36 species of the 38 recorded in Europe can be seen there. However, the most spectacular feature of the region is the colony of Griffon Vultures, inhabiting the crater of an ancient volcano. Cinerous and Egyptian Vultures, Golden and Imperial Eagles are also frequent visitors of the feeding tables. Black Storks nest on the cliffs and Chukars stand sentinel on rocky hillsides. The shrill whistles of Rock Nuthatches and the simple, evocative song of the Ortolan Bunting are heard everywhere around. Other typically Balkan birds, like the Pallid Swift, the Red-rumped Swallow, the Blue Rock Trush, the Black-eared Wheatear, the Orphean, Sardinian, Subalpine and Olivaceous Warblers, the Sombre Tit, the Black-headed Bunting are also common.

Quite different is the view in the western part of the mountain - rounded, pine-clad hills, occasionally cut by streams and rivers winding through deep gorges. One of them is the magnificent Trigrad Gorge - the realm of the Wallcreeper. The gorges resounds with the noise of numerous Crag Martins and Swifts and echoes with the shrill calls of the Peregrine Falcons. Every now and then Dippers, Grey and Pied Wagtails dart over the translucent river.

The range of interesting and colorful plants in the Rhodopes is a feast for the eye - Haberlea rhodopensis, Sideritis scardica, Scabiosa rhodopensis, Saxifraga stribrnyi, Petkovia orphanidea, Trachelium rumelianum, Campanula cervicaria, Hypericum montbretii, Seseli rigidum, Verbascum humile, etc.