The caves and karst features at Cáceres city are restricted to a small area which is called El Calerizo, a name which is also used for the city. This is a geologic structure which is oval and runs from northwest to southeast, with the city Cáceres at the northern tip. A plain which consists of limestone in the center is surrounded by hills made of Silurian, Ordivician, and Precambrian rocks. The structure is a syncline, where the older layers were lifted around the central depression, as a result the youngest rocks are in the center, and they get older with the distance. Under the structure is a massive granite intrusion, which was probably the reason for the formation of the syncline. It is definitely the origin of the neat which caused hydrothermal convection and as a result hydrothermale gangue ore which were mined. So this structure is interesting, both for its karst and its mines.
The karst in the center covers an area of 14 km², and is one of the largest karst aquifers in Extremadura. The aquifer is recharged by rain, but its catchment area is not only the karstified limestone but also the surrounding depression and hills with insoluble rocks and surface drainage. This adds another 16 km² to the catchment area, the brooks go underground as soon as they reach the karst. The surrounding hills are called Sierra de la Mosca, the highest point is at the Santuario de Nuestra Señora la Virgen de la Montaña at 718 m asl, while the central plain is around 460 m asl.
The area has numerous small springs, so it is worthwhile to make a tour and visit a few of them, on the other hand, there is actually no single spectacular karst spring, so we have not listed the small springs. There are several caves in the area, but most of them are archaeological sites which are not open to the public. The most important are Cueva de Maltravieso, Cueva de Santa Ana, and the Cueva de El Conejar.