Craters of the Moon National Monument and Preserve, Idaho

The Craters of the Moon Lava Field, located in southern Idaho, USA, spreads across 618 square miles (1,601 km2) that certainly looks like a lunar landscape. Its scarred landscape is the result of the stretching movement of Earth's crust over the past 30 million years. The more than 60 different lava flows on the surface range in age from 15,000 to just 2,000 years old. During last eruption, lava erupted from the Great Rift, a series of deep cracks that stretch for 52 miles (84 kilometers). The Craters of the Moon continues to be volatile, and scientists predict that it will experience future eruptions that will alter its surface. Surprisingly, this seemingly desolate landscape is home to more than 350 species of plants, 160 species of birds, and 43 mammals.

Source: howstuffworks.com