I dig model trains. My brothers and I had a 6-train platform when we where kids.
Here's one to visit if you're in the Pittsburgh Area. Celebrating it's 90th Season. Very cool with lots of local attractions ie, steel mill, Isaly's, Indiana PA, and the Laurel Highlands including Frank Lloyd Wright's Fallingwater.
http://www.carnegiesciencecenter.org/exhibits/miniature-railroad/