Already mentioned in this thread however the music that plays inside the Diamond Mines, amazing. I had my first visit to EP this past summer, on reflection there were a lot of great experiences, but for me nothing resonates as strongly as listening to the soundtrack that plays there. (Okay well Batavia comes close)
The park was incredibly busy, and the weather was scorching too, and to find not even a single soul on the walkway allowed for a lovely and atmospheric moment of bliss for us. All I heard about the mines was that you shouldn't miss out on it, and I'll happily parrot that to anyone else visiting for their first time too.