In Costa Rica, there are many hot springs fed by water sources naturally heated by a geothermal process (due to volcanic activity). Without a doubt, therapeutic and relaxing effects can be attributed to these mineral waters. Hot springs are more or less developed facilities, but in general, they are located on open property in the middle of an exuberant setting in which it is common to observe the local fauna: toucans, hummingbirds, coatis, monkeys... More than anything, the northern part of the country (where actives volcanoes, such as Arenal, Tenorio and Rincon de la Vieja are found), offers pools with varied temperatures and some even offer games (slides) for children's pleasure. Hot springs are the source of volcanic phenomenons, such as geysers: the largest geyser in the world is the one in Poas Volcano.