I had never even heard of it but it looks like something I would like to get. Just as long as the instructions aren't too complicated.
Thanks for posting the link, BMR. Growing up in Johnson County, Wyoming, my husband has spent time in the "Outlaw Cave" over by Kaycee, Wyoming. "Outlaw Cave" was a hideout for Butch Cassidy. Now that I mention it, it is surprising Outlaw Cave has not been commercialized. My husband says it is a walk down into the earth of about a mile. He lost a jackknife in there once and had to walk back in to get it. Maybe it just seems like a mile getting back out of there...