The planet where Captain Kirk battles the Gorn in the 18th episode of Star Trek should look familiar to fans of the franchise. The same backdrop has appeared in Star Trek: The Next Generation, Star Trek: Voyager, Star Trek: Enterprise, Star Trek VI: The Undiscovered Country (1991), and the 2009 reboot. And the setting isn’t limited to the Star Trek universe: Vasquez Rocks in Southern California has appeared in more than 200 films and television shows, very often doubling as an alien planet.

As Tom Scott lays out in the video below, the landscape's popularity comes down to location: The rock formation lies one mile inside what is known as Hollywood’s Studio Zone. According to Hollywood union rules, whatever locations fall within 30 miles of the intersection between West Beverly Boulevard and North La Cienega Boulevard in Los Angeles are local to Hollywood. If filmmakers want to shoot outside that circle, they have to compensate their cast and crew for travel time. Filming inside the area is therefore a lot more budget-friendly.

The rule is the reason why so many major film studios can be found within the circle. It also explains why so many movies and TV shows set on distant planets aren’t shot too far from the director’s backyard.