The Ag Preserve

City of 2050.
Washington Area real estate is inflated in price for a few reasons: desireablility, and increasing scarceness of developable property. If trends keep up (which they have even amidst a supposed construction slowdown), cities will extend straight out to the-farm. Yes, next to the skyscraper is farmland. No discernable suburbs.
But what about the farm? It's part of the Agricultural Preserve meant to protect farmland, wilderness, and wildlife. It also protects real estate prices by squeezing demand. It's a suburban version of 'historic district'. Even now, one can travel from pure farmland and 'the forest' to an urban, high-rise environment in 15 minutes. I remember when I realized the quick change: I was coming home from "Science City" on the tech corridor, cut though the woods as a short cut, drove by some estates doubtlessly owned by lawyers and Beltway Bandits. Then, a few traditional style suburbs, and then the high rises. 15 minutes. It made a profound impact on me (Cliche :)). Just imagine being a city person, but your neighbor is a cow.

Some prospective Detroit investors plan to use this method to revitalize the city, or, at least, make a quick buck.

Peace with you!