Based on Teebin's posts, isn't the center piece going to be a giant volcano? A Volcano makes me think of Hawaii, or some other island. A backstory about a volcano eruption that carved natural "slides" into the earth from hot Magma, seems possible?
the volcano could rumble and shoot mist/steam? through out the day, giving park guests a sort of mini thrill.
the highest slide would be one from the top or near top of the volcano. Similar idea as Summitt Plumitt.
the park walkways could be sprinkled with water geysers coming out of the ground.
The lazy river will circle the volcano and encompous the inner circumfrence of the park.
Am I on to something here?