Lena River Delta, Russia

A view from space shows the expansive Lena River Delta floodplain, at 12,000 square miles (30,000 square kilometers) one of the world's largest. Resting in Russia's North Siberian Lowland, this Arctic coastal plain has a Dr. Jekyll and Mr. Hyde complex. In the winter it is an unlivable, harsh tundra, but in the spring, it supports a diverse crowd of wildlife, including fish, sea mammals, wolves, and millions of migratory birds. The delta is fed by the north-flowing Lena River—one of the longest in the world at 2,800 miles (4,400 kilometers).