i was looking on a website about never built Disneyland rides. Some of these rides could be cool to incorporate into DL. This information is from wikipedia
A side-street expansion to Main Street USA.
Hollywoodland A Hollywood themed land (DCA) Liberty Street This would have been a sidestreet expansion to Main Street USA themed around an American town circa 1776. (Main Street Expansion)
Geyser Mountain A Twilight Zone: Tower of Terror style ride to be built in the Frontierland. Digging through the mountain in a huge drilling machine, guests would have become caught in a massive geyser and thrown into the air. (Frontierland expansion into pervious space owned by toontown)
Fire Mountain A rollercoaster ride through an active volcano.(Adventureland)