Seeking its own route, the Nisava River cut one of the most attractive gorges in eastern Serbia: the Sicevo Gorge. Some 17 kilometres long, this gorge is composed of the Prosecka Gorge, Ostrovicka Valley and Gradistanska Canyon. The most attractive part of the gorge is the Gradistanska Canyon, with tightly folded walls that are mostly vertical and gradually cut into stone cliffs. The width of the canyon floor is mainly in line with the bed of the River Nisava. The gorge’s cliffs are home to one of the last pairs of Golden Eagles in Serbia. The exit from the canyon has an elevated shape. Significantly, this gorge, along with the Jelasnica Gorge, is the only common habitat of two endemic Balkan species – the Serbian phoenix flower and the Ramonda nathaliae phoenix. The gorge is also home to sage, wild lilac, wild cherry etc.