LARGEST ACTIVE VOLCANO CRATER (in the world?): There are very few places in the world where you can drive up close to the edge of an active volcanic crater. Gasses puff from vents below the observation platform. Surrounding the huge crater is a dense forested area with a unique volcanic flora and fauna. Poas is a stratovolcano in a state of nearly continuous mild activity. Most of the eruptions are phreatic. Phreatic eruptions are steam-driven explosions that occur when water beneath the ground or on the surface is heated by magma, lava, hot rocks, or new volcanic deposits.
