Lava fields as far as the eye can see, flooded caves, cinder cones, fumaroles, hot springs and bubbling cauldrons, the region of Lake Mývatn is the site of much geothermal activity. Popular tourist destinations in Iceland, the lake and the Laxá River that drains it, form a remarkable ecosystem (up to 55 species of bird have been counted here); it has been designated a nature reserve since 1974.