The lake, named after the swarms of gnats that breed around it, is surrounded by wetlands and volcanic landforms, including lava fields, lava pillars, volcanic cones, and boiling mud flats. Iceland lies on the convergence of two tectonic plates and is one of the most volcanically active areas in the world.

(Photo shot on assignment for, but not published in, “In Search of Vikings,” May 2000, National Geographic magazine)