the area around the volcano is a national park. it is a place where many tourists from costa rica and other countries visit. at the bottom of the main crater is a lagoon. the lagoon is an acidic lake with boiling sulfuric gases. the temperature of the lake varies between and . because of changes in the chemistry of the lake and its temperature, the color of the lake also changes. the second crater has a cold water lake in it. this lake is connected to the nearby river, rio angel.