I was on Google the other day and I decided to search "defunct amusement parks".
http://en.wikipedia.org/wiki/List_of_defunct_amusement_parks
It was sad to see that so many parks have failed to prosper, but it was interesting to see all the different parks all over the world. I've read about half of the parks in America and I'm trying to finish be the end of this week. The three most interesting to read about, to me, are Six Flags AstroWorld, Kentucky Kingdom, and Geauga Lake. Just something to do in your free time.