Arenal, Costa Rica

Arenal volcano may be a natural wonder, but living in its shadow requires a thick skin. This formerly dormant peak erupted unexpectedly in 1968, burying 15 square kilometers under rocks, lava, and ash and killing 87 people. Though it has been quiet since 2010, the volcano's persistent magmatic supply means future activity is likely. And the region's humidity, which averages 83% in May, can be a constant headache. Still, the Arenal area offers cultural experiences that connect visitors to the traditional Maleku people, whose lands once included the volcano. For those undaunted by the bureaucracy and environmental risks, Arenal may hold appeal.