North Iceland is a region of vast natural wonders from extensive geothermal activity (see Namaskard gallery) and numerous volcanoes (Iceland sits atop the Mid Atlantic Ridge), to voluminous waterfalls (see Dettifoss, Godafoss, Hafragilsfoss and Selfoss Galleries), to must-see canyons, rivers (Jokulsa a Fjollum and Skjalfandafljot), lakes (Myvatn with its pseudo-craters), to dramatic lava formations and pillars (see Dimmuborgir gallery).