Some pretty spooky stuff:
8 Abandoned Theme Parks Abroad "Open" for Exploration
8 Abandoned American Theme Parks "Open" for Exploration
Video of Six Flags New Orleans (Post Katrina)
For me, the creepiest is "Okpo Land" (First one from the first link). The fact that the car that a girl fell out of and died is still dangling from the track is pretty horrible.
Still, interesting stuff.