Abandoned Six Flags amusement park in New Orleans wrecked by Hurricane Katrina in 2005; submerged at one point under 6-8 feet of water.
I spotted the haunted lines of its empty roller coaster from the Ninth Ward off Interstate 510 while playing tourist in 2009 and begged a friend to pull over to investigate. We found an open gate, infiltrated it, and proceeded to sneak around the eerie, 'end of world' Zombie like setting. An adrenaline enhanced experience I'll never forget. It was like exploring a haunted, adult junkyard theme park on ecstasy, the sick criminal cousin of Disney World. In a good way.
I could have spent days, if not weeks taking pictures on the lonely grounds. Unfortunately I had a crappy point and shoot with me which sputtered out crappy washed out pictures, only a handful of which were salvageable via Photoshop color overcompensation/rejuvenation/reinterpretation.
We were there for about 45 minutes, the entire ruined site to ourselves . . . til we spotted movement across the way and nearly ran, thinking it police. Turned out to be 3 teenage friends wandering in amazement just as we were. When we approached them, they said they thought we were security and spooked, almost fled themselves. We all laughed at the revelation, shook hands, compared notes and moved on.
Soon after, with the reality of other breathing things called 'human beings' in proximity, the aloneness of the place had lost its luster and the fear of trespassing fresh on the brain, we left. Later, I read on the Internet of a few people who had been arrested on the property for trespassing; so our fears may have been justified. However, many more got away with the same as you can find a ton of online pictures of the site, including on Flickr.
I've read conflicting reports of the fate of the place but a few pieces said it was slated for demolition in 2011. For more info. .... Wikipedia: en.wikipedia.org/wiki/Six_Flags_New_Orleans