Tabacón is a natural hot springs resort in the Alajuela Province of Costa Rica, located at the northern base of Arenal Volcano between Lake Arenal and the town of La Fortuna. The geothermal springs are heated naturally by the volcano. 

In addition to Tabacón’s roughly 20 in-river thermal springs and waterfalls, the main pool offers a tropical backdrop with views of the volcano. The pool is filled with natural spring water from the hot springs where temperatures range from 77 to 105 degrees, so it's not artificially heated.

The pool also features a swim-up bar that sits under a giant palapa where guests can hear and spot local wildlife roaming the property grounds.

- Wikipedia