I'm always surprised to here how many people have never heard about Heritage USA. Back in the 80's is was the most visited vacation resort in the nation right behind Disneyland and Disney World; over 6,000,000 people visited annually. It was 2,300 acres (just to give you an idea of how massive this is...when Walt Disney bought land for Disneyland he bought just over 150 acres)
So if park is so grand and mighty, then what happened to it? Two words (actually a name): Jim Bakker. In case you have never heard that name, I'll give you his life in a nutshell: televangelist, did shady things, got caught by the IRS, went to jail.
For a great history of this park (along with some wonderful shots of an abandoned park) visit: http://illicitohio.com/SBNO/heritage/heritage01.html