Monkeys line tree branches covered with mosses, lichens and epiphytes. Reptiles and mammals roam the jungle floors. Life is everywhere. Arenal stands alone on the plain, a classic cone against the horizon. When we learned about volcanoes in school, our textbooks showed a drawing of a perfect cone standing by itself and spewing red hot rocks from its peak.
Few volcanoes are so stereotypical.
But Costa Rica's most active colossus looks as if it came straight from those textbook blueprints. For more than 400 years Arenal Volcano's forest-covered cone sat alone and silent on the edge of the San Carlos plains, exhibiting only a little fumarole activity in its single, dormant crater. In 1968 it erupted violently without warning, spewing molten rock and ash high into the sky, destroying the village of Pueblo Nuevo, killing 78 people, and forming three new craters. It has been active ever since with more or less regular eruptions of lava and ash providing fiery demonstrations that draw curious onlookers from all parts of the world. Arenal's constant activity has covered the two lower craters on the western, rocky slope.