Bolii cave.

Bolii cave belongs to the protected area of the Natural Park Grădiștea Muncelului- Cioclovina and is located 6 km North of the town of Petroșani, on the road that connects the Jiu valley to Hațeg county, at the place where the Retezat Mountains meet the Sebeșului Mounts. Bolii cave is the only cave in Romania crossed all along its 455 m length by a river; it can be visited. The name of the cave probably comes from the family Bolia who had, as early as the 15th century land and forest properties in the area. In the 60’s, in the cave were built bridges across the water, but they were destroyed in time. The cave was abandoned until not long ago, when it was enhanced by the Ecological Association Petroaqua of Petroșani. The cave starts at the point where the Jupâneasa rivulet absconds into the Jurassic limestone wall, through a spectacular portal, 20m wide at the base, and 10 m high. The main gallery of the cave is generally large, in places turning into really wide halls. Drainage formations appear in high places and on the ceiling of the cave. For a length of 466 m the gallery descends only 3 m. At present, there are footbridges that ease the passage through the entire underground void in perfect safety. The hall was named the Concert and Dance Hall, due to its outstanding acoustics; as early as the inter-war period, they organized concerts here.