The cave is a 262-meter-long natural rock bridge. There are 2 entrances - large and small. From the small entrance with a height of about 35 m walks a path that passes through the whole cave and goes through the big entrance (the biggest cave vault in Bulgaria - 45 m).
Prohodna Cave is naturally illuminated by the huge entrances and natural openings in the attic - "okna". It is the " eye" that makes the phenomenon "God's eyes". Located side by side, with the same almond-shaped shape, looks amazingly like huge eyes that seem to be staring at the visitors.
The site is part of a cave corridor, which faces from east to west. It was formed at the end of the Credit Period 66-68 Million years ago. In the past, the waters of the Iskar River have filled the cave. Now the level of the river is below the cave floor. As a result of the active karst processes, characterized for this period, seismic activity and river activity, the cave-shaped cave corridor was interrupted and this part remained separate.
The location of the Prohodna cave allows for one-day excursions from almost the whole of southern Bulgaria.
