The Matterhorn is an extremely short ride at disneyland. It gets it's concept (and name) from the famous mountain in switzerland. It also partly lies in Switzerland. But the most important thing about the ride, is that it is a couples ride. Since it derives its inspiration for a mountain, the ride somewhat imitates a member of a toboggan. The cars are two-seaters, and one person sits in front, and the other sits behind and puts their legs around them. You must act as a couple to ride the matterhorn, but of course, you aren't a couple when you get off. This, of course, mirrors the chorus "is it the same as before, when we went down the matterhorn/one cannot be too sure/it's different on the matterhorn/our love encased in ice forever" The matterhorn is also situated relatively close to "tomorrowland", which is the sector of the park that contains the starcade, space mountain, and the carousel of progress.
There was also another ride at disneyland, called, I believe"20,000 leagues under the sea", but everyone called it the submarines. You had a "submarine journey" by submersing a small capsule in a pond, where they had statues and animatronic creatures underwater. The ride has closed, since, which is where "in line for submarines/forgetful you" comes from.
Starcadia has a mixed heritage. The song is most definitely about a ride in disneyland called "Space Mountain" according to ronnie. However, the song itself gets its name from an arcade that lies adjacent to space mountain aptly titled "starcade". A friend of mine tried to listen to Starcadia while on the ride Space Mountain, but his CD player ran down. Space Mountain is an indoor roller coaster, and there are no house lights while you are on the roller coaster. Therefore, is is quite nearly pitch black, simulating, of course, space. There are, however, lights imitating stars, neon lights, and the like inside. Unfortunately, the ride is closed until 2005 while they redo the track.
The Carousel of Progress is an interesting attraction, more of a show than a ride. The show is arrange concentrically, so to speak. The stage is circular, and the audience sits on a circle outside. The audience moves carousel fashion around the the stage, and each time they move, they see a different part of history, sequentially. The last part is the not-so distant future. The cast is made up of animatronic people. The ride was shut down recently.
Many thanks to Captain Negro for writing all of this on the JE boards.