This is what Space Mountain looks like with the lights on

Space Mountain, the indoor roller coaster is one of the most popular rides in the Magic Kingdom.
Most riders never get to see how it's put together because it runs in complete darkness. The people that shot this video got a chance to ride through the building via the Peoplemover.  The lights were on and you get to see the inner workings of Disney magic, including the dome, track and other infrastructure.