If we had to name places no longer in existence that we would like to have visited, the list would include the Hanging Gardens of Babylon, the Colossus at Rhodes and the World of Sid & Marty Krofft. The World of Sid & Marty Krofft was a theme park opened by the men responsible for "H.R. Pufnstuff," "Land of the Lost," "Lidsville" and other trippy "kids" shows in the '60s and '70s. It was located in Atlanta, Georgia in a crime-ridden section of downtown that today is home to CNN and Centennial Park. Because of continuously malfunctioning rides and poor attendance (see the above bit about crime), the park closed less than a year after it opened in 1976.
There's not much remaining about the park. Here's a small memorial site with some brochures, ads and a map of the park that's too small to read. The owner of the site has promised for years to update it, but no such luck.
Thanks to Atlanta's Creative Loafing, there's also this retrospective article that's pretty comprehensive in its detail of the park experience and its rise and fall. The article describes the park as a "tangible LSD trip for the whole family." Perhaps that was another reason it didn't stay open too long.
Alas, we're forced to imagine what it must have felt like to ascend the 205-foot-long escalator, ride around in an enormous pinball and chat with Tina Tarantula.