You have got to see this to believe it. We've got a massive underground cave here in Idaho and it might be right under your feet!

It's called Bear Trap Cave, and it's located near Craters of the Moon National Monument.

The crazy thing about this cave is you may not even notice it at first glance. In fact, you can be right on top of it and not recognize it is there. When you get to the right angle though, all of a sudden you see this ginormous opening.

The history behind Bear Trap Cave is insanely cool too. It's thought to have originated 15,000 years ago from a lava tube. To put things into perspective, according to onlyinyourstate.com, the Craters of the Moon lava flow is thought to be about 2,070 years old.

When I say massive, I mean massive cave. Bear Trap Cave is about 15 miles long and without a good flashlight, you're in complete darkness most of the way through.

So, next time you're near Craters of the Moon, check this place out! Just be careful, rattlesnakes are can often be seen handing out in Bear Trap Cave during the summer!