This museum has thousands of model trains as well as a huge model railroad city with many tracks, mountains, ponds etc. When we were there 4 trains were running. I would say it is about 40 ft by 60feet in size. See their web site for many more pictures: http://www.smokymountaintrains.com/index.shtml
Even those who don’t think they are interested in models will be hooked. They have a cute scavenger hunt where you can look for all kinds of cute tidbits in the city. I counted at least 50 cabinets each with at least 40 train cars. They range in price from $50 to $2500. All from two collectors! Bob took movies but I have not seen those yet.