The geological reserve is a nature conservation area, an area protected by law for its geological or paleontological importance. Such reserves are either outcrops rich in fossils (fossiliferous points or places), or rocks or minerals of different types, or natural openings that illustrate different geological processes (plate tectonics, formation of mountains, oceans, volcanism, etc.). Geological reserves are protected both for conservation and as places of study or research, having, in addition to the scientific value, a great educational value. According to their importance, the reserves are classified in different IUCN categories. IUCN category III includes natural monuments, and category IV includes geological, paleontological or mixed nature reserves. Some reserves are included in larger protected areas, such as various sites of the Natura 2000 network, national parks, natural parks, or in sustainable development territories, such as geoparks.