Let me give you a quick explanation.
When Sesame Place opened in 1980 it featured a play element that was essentially a giant water bed:
Image from CardCow.com
It was eventually re themed to be a splash pond (with the same name):
Image from Google Street Views
I did a post about both versions of this attraction covering cute details of what the statues of Bert and Ernie "caught" as they fished. You can read that here.
One detail that I didn't cover was the slide to the left of the statue:
Image from Webshots
The slide was designed to look like a boat that was washed up on some rocks. A ladder entered at the top where a hunk of the boat was missing. Kids then slid down to the bottom where another piece of the boat was open, letting them slide right into the pool.