Prohodna Cave

Prohodna is a through-cave: a tunnel about two hundred and sixty metres long open at both ends, with the larger entrance around thirty-five metres high, so daylight runs the whole length and no lighting is needed. Near the middle, two almond-shaped holes have opened in the roof side by side, and from directly below they read unmistakably as a pair of eyes looking down, which is where the name Oknata, or the Eyes of God, comes from. In rain, water falls through them in two streams. The cave is used for bungee jumping from the roof openings and for climbing on the entrance walls, and the surrounding Karlukovo karst holds several hundred more caves and is the centre of Bulgarian caving.

What you actually see

• The two roof openings - the eye-shaped holes seen from directly below.
• A through-cave with daylight - open at both ends, no lighting needed.
• A thirty-five-metre entrance - the larger of the two mouths.
• The Karlukovo karst around it - several hundred caves in the area.

When to go

April to October for comfortable walking; the cave is open at all hours and free year round. One to two hours. Rain makes the eyes stream, which is worth timing for if you do not mind getting wet.

Honest expectations

The floor is muddy and slippery and there is no path or lighting. Bungee operators use the openings, which brings noise. There is litter and graffiti in the cave. Karlukovo village has very limited facilities.

Nearby

The Iskar gorge runs south; Devetashka cave lies east.