The “Hole with Fly” cave is located 12 km downstream from Moldova Noua, Caras Severin county, at approx. 30 m above the level of the Danube. You can reach the place from the road that crosses the Danube Gorge, 12 km downstream from Moldova Noua, in the place where you find a source of drinking water. It was inhabited during the Hallstatt period, being an ideal shelter for primitive men. Its position, with an entrance that dominates the Danube, was ideal for defense, so in medieval times it has been fortified and armed with guns and a small garrison of soldiers. Today we can see the entrance fortifications done from 1460 and rebuilt several times, used up by 1880. The cave was named “Hole with Fly” because, according to a legend, it’s the birthplace of the terrible Columbaca fly (Culex columbacensis) that came out of one of the 12 heads of the dragon killed by the hero Jovan Iorgovan. In the Middle Ages, this fly killed many animals. The cave is oval shaped, with 8 and 4 m diagonals, blocked largely by the medieval fortification walls. The access gallery is middle sized and draining a watercourse. The route passes through the Bat Hall and reaches a terminal drain, with stalactites, stalagmites and deposits of montmilch. Inside the cave there is a strong ammonia smell, due to bat guano deposits.