Arenal is most active volcano in Costa Rica. Its earliest eruption was about 7,000 years ago. Its most recent eruption was in 1968, after it had lain dormant for 400 years. The ancient volcano rises more than 5,000 feet. It sits in the Arenal Volcano National Park, a 47-square-mile protected area. The Guatuso Indians who lived in the Arenal area for thousands of years believe the volcano was home to the God of Fire. (SHAFER & HILL—GETTY IMAGES)