The Sicevo Gorge is part of Nisava River, located 14 km east of Nis, between the villages Prosek (downstream) and village Dolac (upstream). It is about 17 km long and connects Nis basins with the Bela Palanka basin. It is also the shortest connection between the middle and lower Ponisavlja region, or between the upper and lower middle Nisavlje region.
The gorge is divided into two geographical units: the upper – Crncansko-gradistansko canyon, and the lower – Ostrovicka gorge. The upper part is narrower and more like a canyon (from Ostorvice to Dolac), while the lower (from Prosek to Ostrovice) is wide with gentle slopes.
The gorge is surrounded by the Svrljiske Mountains from the north and the slopes of Suva Mountain to the south. Through the Gorge, in parallel with Nisava River, a railway was constructed in 1886 and international highway in 1964. The Nisavska Railway is part of large international rail routes (London-Paris-Belgrade-Nis-Sofia-Istanbul), and the main road E-80, is the eastern branch of Corridor 10, part of a large pan-European route (Salzburg-Zagreb-Belgrade-Nis-Sofia-Istanbul) and connections across Asia Minor to other areas of the world.