From one reason to or another, theme parks tend to get closed. Some fall on hard times and cannot pay their employees and take care of the upkeep. A lesser known reason could be because an accident occurred and or there was some extensive damage to the facility. If those reasons were the case, why not change some of these places into Haunted Attractions or donate/sell them to the city/state they reside? Maybe they can find something to do with the places. In my opinion, leaving these places standing is harming the environment. If these places aren't being used nor can they be sold/donated, maybe they can be destroyed and the area planted with plants that can thrive in that area. Below are some of the theme parks that have been abandoned over the years.
1. Six Flags in New Orleans, Louisiana
Before Hurricane Katrina made landfall in 2005
After Hurricane Katrina
2. River Country in Orlando, FL
Disney World's first waterpark which is now being reclaimed by nature
3. Santa's Village near Lake Arrowhead, California
This was once the first franchised theme park around the world
4. Rose Island in Charlestown, Indiana
This once beautiful place was ruined by a flood
5. Rock-A-Hoola Water Park in Newberry Springs, California
Putting an "oasis" in the desert seemed like a good idea