The two models for master-planned communities both date back to the 1960s: Irvine, in southern California, and Sun City, outside Phoenix.

ECONOMIST: The growth of private communities

The sun-drenched 19th and 20th floor residence has floor to ceiling glass walls, a master suite with a fireplace and French doors opening to a terrace, and an oversized master bath and dressing room.

FORBES: Calvin Klein Compound, Manhattan, New York

Steroid Cities are those fast-growth metro areas, mainly located in America's South and West, where the sun shines, the air-conditioners hum and the two languages you'll need to master in addition to English are capitalism and Spanish.

FORBES: Steroid Cities