On GuardA ranger stands before the 65-story-tall lava plume of Nyamulagira volcano, Africa's most active, which roared back to life last week in the Democratic Republic of the Congo (DRC).Virunga National Park, famed for its rare mountain gorillas, has quickly seized on the display as a way to boost tourism, establishing an overnight tent camp nearby (but not too near), officials announced this week.(See an interactive cutaway of the Nyamulagira volcano region.)Sitting up through the night and watching enormous geysers of liquid lava dance in dark skies was "the coolest thing I've ever seen," said Cai Tjeenk Willink, head of development at the park.Virunga National Park, embattled by a 12-year civil war and persistent political instability, is patrolled by 360 armed park rangers, who guard against wildlife traders as well as militia and rebel groups. Safety has improved dramatically in the past several years, Willink said."The main function of the guards is to act as a deterrent," he said. "We always bring armed guards with our visitors. We value the safety of our visitors and invest in supplying this safety."—Brian Handwerk

Photograph by Cai Tjeenk Willink, Virunga National Park