In the daytime, it is a very special experience to see clouds of ash and smoke billowing into the sky from Arenal's crater.

On clear nights, spectators are occasionally treated to a natural fireworks display, when an eruption of lava and burning rocks explodes into the air and showers down the cinder cone. Even when it's overcast, the rumblings, venting and molten lava glowing eerily through the clouds, make for stirring spectacle.

Arenal Volcano, and the bustling town of La Fortuna nearby, are some of Costa Rica's most popular destinations, and thousands of people flock there every year to see the colossus. On Aug. 23, 2000, Arenal Volcano erupted unexpectedly, killing a tourist and a naturalist guide, so much care must be taken when visiting the area.