Komárom-Esztergom is a county south of the Danube and west of Budapest. It is at the eastern end of the Transdanubian Hills, and has several areas with low hills separated by plains. The main hill country are the Gerecse Mountains. The northwest of the county is lowland. The rocks are sedimentary rocks of Mesozoic age with coal and bauxite as main resources. There was some coal mining in the area. In the hills there are numerous caves, renowned among cavers for extraordinary speleothems like calcite crystals, aragonite, gypsum and even other minerals. There was a hydrothermal phase which is responsible for the formation of those mineral deposits. While the caves are special, there is no show cave in the county.