Prohodna Cave

thumb|The Big Entrance of Prohodna (Passage) cave with visitors for comparison of height right|thumb|The Eyes of God formation in the Prohodna cave|alt=Two eye-like holes in the ceiling of a cave letting light in Prohodna () is a karst cave in north central Bulgaria, located in the Iskar Gorge near the village of Karlukovo in Lukovit Municipality, Lovech Province. The cave is known for the two eye-like holes in its ceiling, known as '''God's eyes'.

Prohodna is the best known attraction in the Karlukovo Gorge (part of the Geological Park Iskar-Panega), one of the largest karst regions in Bulgaria and a popular location for speleology. Formed during the Quaternary, Prohodna is long, which makes it the longest cave passage in Bulgaria. The cave has two entrances which lie opposite one another, known respectively as the Small Entrance and the Big Entrance. The former is high and the latter reaches in height. The cave owes its name, which literally means Thoroughfare Cave or Passage Cave, to this feature. The size of the Big Entrance of Prohodna makes it suitable for bungee jumping, and it is among the popular spots in Bulgaria for that activity. There are traces of prehistoric habitation in the Prohodna cave, which testify that humans lived in the cave during the Neolithic and Chalcolithic.