From what I’ve read online 20,000 leagues took up most of what is now the new fantasyland, which includes 7DMT. The water was still there in the early 2000’s. There was a statue of Triton in the water next to the Little Mermaid play area/meet and greet.
Toon Town was turned into the circus area. The coaster, train station, and large circular buildings on the left (gift shop and meet and greets) were there when it was Toon Town. They’ve just been rethemed. I miss Toon Town! Mickeys mailbox is in his meet and greet gift shop exit, up high above all the stuff for sale.