Wikipedia and Muppetpedia on Fraggle Rock, the Muppet show everybody my age just barely remembers. I know I've spent a good amount of time in recent years trying to remember the specific geography of the human home in relation to the giant Trash Heap -- turns out they're just in separate directions.

The sites also detail the specifics of the Fraggle/Doozer ecosystem, if such matters are important to you (they are of great importance to me).

Another tidbit: there's apparently a Fraggle movie coming in 2007.