In the American entertainment industry, the studio zone (also 30-mile zone) is the area within a 30-mile (48.3 km) radius from the intersection of West Beverly Boulevard and North La Cienega Boulevard in Los Angeles, California. In addition, the studio zone includes the Metro–Goldwyn–Mayer Conejo Ranch property, although it technically lies outside of the zone's radius.
http://www.tmz.com/