When I was a kid (read well into college), I had a 12 by 12' LEGO city. A good 1/4 of the town came one Christmas morning when, upon my mother closing her toy store, she had saved some two dozen sets for my sister and I--that is one of my fondest Christmas memories as we tore into package after package of LEGO sets.
Sometime in early college my dad got a pool table, and I came home to dismantle most of the town, but still tried to have one along a 1' strip around the basement walls (double decker roads and all). It got stepped on frequently, so it eventually came down. Every set is labeled, baggied with instructions, and in one of five large plastic tubs in my basement now. Some day, the city shall rise again.