Trust me, I'm The Doctor.
I stuck this under technology because of the fact that it takes a good bit of technology to make one of these beasts. I frequently read a web site called The Roller Coaster Database. It's a huge database of theme parks, run down parks, and side-of-the road roller coasters of all types. It's very interesting to read about the ones that have been relocated several times, torn down, or are just standing there taking up space and not being run. Some are even accompanied by stories of their demise, or history.