The Trigrad Gorge

The Trigrad Gorge is a canyon of vertical marble rocks in the Rhodope Mountains. The gorge encloses the course of the Trigrad River, which plunges into the Devil’s Throat Cave and 530 metres (1,740 ft) further emerges as a large karst spring. It later flows into the Byunovska River.

The gorge is 1.2 kilometres (0.75 mi) from the village of Trigrad at 1,450 metres (4,760 ft) above sea level and has a total length of 7 kilometres (4.3 mi), of which the gorge proper comprises 2–3 kilometres (1.2–1.9 mi).