disneytrivia:

The original Disneyland Haunted Mansion required clever space management in a theme park that has always contended with a lack of space. When the New Orleans Square area was added in the early 1960s, there was no more room in that quarter of the park for large attractions. The Imagineers therefore placed the bulk of the Haunted Mansion ride outside the theme park’s boundaries. The famed “stretching rooms” are actually elevators, implemented simply so guests could be moved underground. Most guests do not realize that the portrait hall is actually an underground passage leading under the berm behind the mansion facade. As they enter the loading area, they pass beneath the Disneyland Railroad’s tracks and into a vast, approximately 37,000 square feet (3,400 m2), soundstage-like show building located outside the park boundaries.

I totally made it to the Finals for the Portkey Trivia Contest :D You should all go!!