Disneyland in California is the only Disney theme park with a Matterhorn Bobsled ride. The tracks of Space Mountain at Walt Disney World's Magic Kingdom were based on the designs of the Matterhorn but are not identical to them. The Matterhorn's newer bobsleds, added in 1978, were based on the other ride's rockets, which had debuted in 1975. When Space Mountain was built at Disneyland, it was a completely new design with a single track and vehicles that seated riders side by side rather than behind one another. Various proposals to bring the Matterhorn to Walt Disney World existed over the years, but none came to fruition. The most detailed concept was for the Matterhorn to be the main attraction of a Switzerland Pavilion for the World Showcase at Epcot, but this failed when Disney could not secure a sponsor.