In the 1960s, NASA needed to prepare astronauts for walking on the moon's surface, so it searched for the most lunar-like landscape on Earth.

When they found it, it seemed almost unbelievable that such a place could exist on Earth. Imagine: A vast expanse of black volcanic rock so alien-looking that it could double for another planet. The terrain is so convincing that Apollo astronauts spent weeks there learning to navigate in spacesuits, collect rock samples and operate equipment in conditions that mimicked what they would face on the lunar surface. Four different Apollo crews trained on this strange landscape before their actual moon missions.

When you see the place, you can understand why NASA made this choice. The ground beneath your feet is a sea of hardened black lava, twisted into rope-like formations and dotted with ancient volcanic cones. In some places, the lava formed underground tunnels so large you can walk through them. The landscape stretches for miles in every direction, broken only by occasional patches of hardy wildflowers that somehow manage to survive in this harsh volcanic soil.

Can you guess where in the world this place is located?

This is Craters of the Moon National Monument in south-central Idaho, where 618 square miles of volcanic landscape earned protection in 1924. The name comes from early explorers who found the desolate terrain suggestive of the way they imagined the moon's surface. And it turns out, they weren't so far off!

Would you like to walk where astronauts trained for the Moon? Let us know in the comments!