It was appeared about millions years ago. It means "the corner of old lady" and is attributed to indigenous people of the Guatuso tribe living on the eastern side of the volcano who believed that an old witch lived on top of the mountain and would send columns of smoke into the air whenever she got annoyed. It has 9 craters (Rincon - 1.806 m.a.s.l., Von Seebach - 1.895 m.a.s.l., Santa Maria - 1.916 m.a.s.l.) and is considered as the third in respesct of activity volcanoe in Costa Rica. (Santa Maria crater is considered to be by some people as the separate volcano). It`s main crater has elipse shape, 500 metres of width and 100 metres of depth. On its bottom there is a hole with bumbling 250 Ceisius lava. In April 2000 the Canadian tourist has fallen to there for three days. To the east of crater there us a lake, waterfalls and bubling holes. In the terrain called Las Hornillas , the fumaroles hiss like kettles spitting up odiferous steam and gases. The last vital eruptions took place in 1966-1970. They were accompanied by clouds of ashes, earthquakes and tremors. The lighter eruptions took part in 1984, 1891 and 1996.