Mammoth Cave is amazing isn't it? One of the entrances to it is only 2 miles away :D
And I highly doubt there is a billion cars in the world
Yeah it was like 95 degrees when I went. Normally we would have kept our dogs in the car, but we had to board them all day. After they were boarded we went to the Corvette factory (saw ZR1s on the assembly line

), then went to the museum where we took pictures of like 40 different cars (the two I posted included that are now down in that hole), and finally went to mammoth cave. Went from like 95 degrees outside to 75 under the trees to like <60 down in the cave. I wanted to live down there.