A hike outside of Columbia. There are these huge caverns cut out of the bluff for limestone (?)... The government found it to be a great site to house thousands of documents and formed the National Archives. Sorry, no space aliens or goblets of fire.
The Boy Scouts made a well groomed trail up to the top with miles of windy trails and excellent views of the river bottoms. On the back side you end up at the Archives. SO, you could walk ALL the way around to the front of the trail - OR - make a short cut through the very dark, and a bit daring tunnels dug through the bluff. It's not recommended.. there are boulders in the ceiling that appear to be held by the slightest bit of pebbles and dust. It's amazing how big the tunnels are - they haven't been mined for some time - and they look to go into the bluff for a long way. No bat warning - and we didn't see and signs of them. Most caves that have bats have been completely shut off from the public due to "White-Nose Syndrome".
