There was once a bluesky plan within WDI to add a Vulcania/Discovery Bay section to the Magic Kingdom. I drew this conceptual site plan to explore where such a land could go and how it might be laid out:
The key to expanding north of FLE would be a themed bridge that goes over the East-West access road and keeps all those backstage areas from view. Tokyo DisneySea has just such a bridge leading to/from its Mysterious Island:
Discovery Bay would be home to a version of Journey to the Center of the Earth, but with an extended outdoor section that drops out of the volcano's side and does two high speed helices above and below the shoreline and around a smaller caldera before re-entering the volcano for disembarkation:
Since such an expansion would require an alternate western access point, I imagined WDI planning two new sub-areas to Frontierland: a gunslingers town called Outlaw Ridge with its associated E-tick and an area I call White Canyon based on Pueblo cliff dwellings. There would then be a wilderness trail looping around the Rivers of America and connecting with Discovery Bay (with its 1880s San Fran/Barbary Coast motifs).
In this plan, I also explored the recently-discussed idea of creating a Wonderland sub-area to Fantasyland (with the recently re-named Cheshire Cafe). In this plan, Cosmic Ray's would become the Queen of Hearts banquet hall, the teacups would receive the glass petal roof and the northern half of the Speedway would be given over to a Giant Mushroom Garden play area and new Wonderland dark ride (LPS) that begins in an English Country House. This would make a thematically consistent transition from the Hub to Fantasyland. (with a new archway added to transition to Tomorrowland:
Since this is an ideal build-out site plan, I drew my hopes that Tomorrowland would one day be brought under a coherent thematic umbrella of Deco-Tech Industrial Fantasy Future. I added a walkthrough futuristic power plant based on the Large Hadron Collider over the southern half of the Speedway (to keep some of the trees/greenery in the land) and added an large, original E-ticket taking over the the Carousel of Progress & parking lot.
Thoughts on a long-term expansion plan for the MK?