one of my friends built a huge train getup in his garage. they mounted it on a sheet of 4x8 plywood, laid track, built mountains and villages and roads and shops, etc. the thing was amazing. his dad even put in a pulley system so they could lift it up and park the car inside. they spent months putting it all together.
in the time we were neighbors, i saw him lower it and run the train twice. that was in a span of 14 years. as far as i know, it's still hanging in his parents garage, and must have a pretty impressive amount of dust on by now.