the same time, the destruction of the earlier Paleozoic rocks formed enormous quantities of gravel, sand and clay, which were deposited by the rivers into the sea basin. The sediment piled up and gradually became thicker layers of conglomerates and sandstone, with the conglomerate pieces becoming well rounded over time by the forces of water. During the Jurassic period, over a period of 20 million years, the layered materials became firmly glued together by sand-clay solder or silicon. The hot and dry climate formed a great amount of iron oxide, or hematite, which gave the rocks their rusty red color. When the earth's crust started to settle, lighter and smaller sandstones merged with the red conglomerates. At the beginning of the Cenozoic era and the early Alpine tectonic cycle, large anticlines, or folds were being formed in the Balkan Mountains, and during this time the region turned to dry land. About 45 million years ago, the rising of the Belogradchik anticline began, and during this folding, the limestone and the conglomerates in the core cracked, creating vertical and horizontal rifts in the ridge of the anticline. In the core of the Belogradchik anticline, Paleozoic rocks are found and the slopes are formed of conglomerates, sandstone, and Jurassic limestone. The vertical penetration and surface rivers favored vertical erosion of the rock layers, and the rifts, where tectonic movements occurred, were transformed by the erosion in small valleys and passes with vertical or steep slopes forming separate vertical blocks seen today as the rock figures. Tourism The Belogradchik Rocks are a major tourist destination in northwest Bulgaria, along with the town of Belogradchik and the Belogradchik Fortress, which incorporates the rocks as part of its natural defense, and the nearby Magura Cave, situated near the village of Rabisha. Another tourist attraction in the area is the Baba Vida medieval fortress in the nearby town of Vidin on the Danube river. The Bulgarian Committee of the Natural Environment declared the rocks as a natural monument in 1949, and the rocks were listed in the Bulgarian National Register of Natural Landmarks in 1987. In 1984, the Belogradchik Rocks and the Magura Cave were both placed on the Tentative List of places to be named to the UNESCO World Heritage Site list. The Rocks are under consideration as a Geopark in the European Geoparks Network and the UNESCO Global Geoparks Network. In September 2008, Belogradchik