A boiling mud pool in the Rincon de la Vieja region. Photo by Steve Jurvetson
Rincon de la Vieja is a satanically misshapen volcanic landscape of craters and pools and bubbling mud. Good for hiking, riding and simmering in hot springs.
A thermal spa supplied by warm, mineral volcanic springs is a must-do after a hard day’s hiking or other activities, but this is not the place for it, unless you fancy being boiled alive. The Arenal area in particular is packed with superb, beautiful spas and layered pools spectacularly configured into both natural and stylish-but-unnatural environments.
These hot springs come from underground water that is heated by volcanic vents and forced upwards toward the surface passing through mineral deposits and gases which dissolve in the water. Cloudy pools have high levels of minerals dissolved in them whereas clearer pools have roughly the same mineral content but they are less dissolved.