The Los Azufres Park is known for its thermal waters heated by an inactive volcano. The site extends over 1319,15km2 with an altitude that varies between 2950 and 3200masl, near San Pedro Jácuaro. The springs have been attributed with medical powers since the pre Hispanic period. A number of spas have been established in the area such as Laguna Larga, San Alejo, Doña Celia, Campamento Turístical Los Azufres, Tejamaniles, and Eréndira. The tranquil waters of Laguna Larga reflect the green of the trees around them. Laguna Verde is colored by the sulfur it contains. In a number of places there are craters where mud boils. In Laguna Los Azufres the water is very hot and contains a large quantity of dissolved minerals including sulfur. There are also geysers and fresh water springs. It is not a national park but Semarnat has a project to declare it a protected area. Problems with the area include deforestation and trash. The geothermic energy of the area is used to generate electricity. There are various hotels, spas and other businesses which offer activities such as camping, cycling, rowing, swimming and hiking.