Individual volcanic park descriptions are listed on the menu to the left. 

The geological activity that led to the formation of Costa Rica's volcanoes continues today generating the spectacular eruptions at Arenal and the boiling mud pots, geysers and hotsprings at Irazú, Rincón de la Vieja and others.

The plates that make up the earth's crust are constantly in motion. Right now the plate off the Pacific Coast of Costa Rica is moving to the east. (©2006 Toucan Guides)

As the Pacific plate moves east it slides under and lifts the Atlantic plate in a process called subduction. (©2006 Toucan Guides)

Eventually the Pacific plate is pressed down into molten core and begins to push lava towards the surface. When the lava reaches the surface in places like Arenal Volcano, eruptions occur (©2006 Toucan Guides)