there was this really wierd series i saw a long time ago on very late night tv, like the arc 2 or something like that.  it was a spaceship that housed these civilizations from earth that was going to crash into a sun.  the people lived in huge domed environments  that stuck off the side of a long middle piece, and didn't even know in many cases that they were on a space ship.  there were a lot of wierd social structures...i specifically remember one where the society was a midevil society enduring a plague.  the adventurers were attempting to get through the domes to get to the controls to keep the ship from crashing in a long storyline.

 

that thing was probably pretty big.  i don't know if it is a 70's or 60's thing.