Orlova Chuka Cave
Orlova Chuka Cave is located within the lands of the village of Pepelina and is perhaps one of the most well-known destinations in the region. The name of the village and the name of the cave are inseparable—as anyone can verify with a quick online search.
Orlova Chuka was discovered by chance in 1941 by a young goat herder. Since then, the cave has been continuously studied. During excavations in 1961 by archaeologist Nikolay Djambazov, parts of cave bear skeletons and flint tools were found in a niche near the entrance. The archaeologist concluded that the cave was likely used both for shelter and for ritual activities connected to successful hunting. The time when cave bears disappeared from Europe, combined with the manner and quality of the flint tool crafting, suggests that the cave was inhabited over 40,000 years ago.
Later studies show that Orlova Chuka was also inhabited during later periods, albeit intermittently. This is evidenced by fragments of pottery with decorative patterns dating from the Chalcolithic period (5000–4200 BC) and the Iron Age (1000 BC). No further archaeological excavations have been conducted.
The development of the cave for visitors began in 1959, when 124 steps were carved into the rock and an artificial entrance was dug. In 1961, electric lighting was installed, and by 1970, 80 spotlights illuminated a one-kilometer trail through the cave’s depths.
The explored passages of Orlova Chuka extend for more than 13,400 meters, making it the second longest cave in Bulgaria (after Duhlata, at 17,600 meters). The air temperature in the galleries is almost constant at 14°C, with seasonal variation of only 1–2 degrees. Most of the tourist path is flat and covered in dry clay, making the cave suitable and safe even for small children.
The cave was formed through various geological processes. The limestone that forms the canyons of the Rusenski Lom tributaries originated from sediments deposited in a warm Cretaceous sea. After tectonic uplift, the sea withdrew, and riverbeds were formed, slowly eroding the terrain. For centuries, water dissolved parts of the rock, creating not only spectacular surface formations but also a unique network of tunnels and galleries deep within the stone.
As often happens in nature, the same processes can alternate, yielding entirely different results. In Orlova Chuka, erosion and deposition resumed their work—with water droplets as their only tool. Over millennia, nature has sculpted unique cave formations. Today, the cave features stalactites (hanging from the ceiling) and stalagmites (rising from the floor). When they meet, they form columns called stalagnates or flowstones, which continue to grow in diameter over time. Another deposition form is the “draperies”—rock formations resembling stone curtains hanging from ceilings and walls. The rate of formation depends on many factors, especially the limestone content and dripping frequency. In Orlova Chuka, it takes about 100 years to form just one centimeter.