The western of the two calderas is partially filled by a crater lake, Lagoa das Furnas, at an elevation of and populated by several fumaroles and mud pools are located at the northern part of the lake. In the central part of the village, springs and geysers are prevalent; thirty springs, each of differing temperatures and chemical compositions, including warm iron-rich streams and piped examples of mineral-rich warm and cold water. The geysers are situated in several basins rich in sodium bicarbonate, boron, fluorine and traces of carbon dioxide. The local inhabitants cook corn-type dishes in the geysers. The installations of hydrotherapy are in the park and were built in the 19th century.