The first thing you'll see when you approach the Magic Kingdom by Monorail or look out from a balcony at the Grand Floridian, Polynesian or Contemporary is most likely the 180 foot tall structure housing Space Mountain. Space Mountain is one of the fastest roller coasters at Walt Disney World. You will board a rocket that is then launched into space. This ride is almost completely in the dark and a lot of fun. It is one of my very favorites.