Back lot

A backlot is an area behind or adjoining a movie studio, containing permanent exterior buildings for outdoor scenes in filmmaking or television productions, or space for temporary set construction.

Some movie studios build a wide variety of sets on the backlot, which can be modified for different purposes as need requires and "dressed" to resemble any time period or look. These sets include everything from mountains, forests, ships, to small-town settings from around the world, as well as streets from the Old West, to whole modern-day city blocks from New York City, Paris, Berlin and London. There are streets that comprise an assortment of architectural styles, Victorian to suburban homes, and 19th century-style townhouses that encircle a central park with trees. An example of this is "Forty Acres" in Culver City, California or, in the case of Universal Studios, the home of Norman Bates from the Hitchcock movie Psycho.

The shells, or façades, on a studio backlot are usually constructed with three sides and a roof, often missing the back wall and/or one of the side walls. The interior is an unfinished space, with no rooms, and from the back of the structure one can see the electrical wires, pipes, beams and scaffolding, which are fully exposed. Ladders are usually built into the structure, allowing performers to climb to an upper-floor window or the roof to perform scenes. Not all the buildings and houses are shells. Some are closed in with a fourth wall. When not otherwise in use, they serve as storage facilities for lighting and other production equipment. When in use, the structures are dressed by adding doors, window treatments and landscaping. L-shaped temporary walls are placed inside of doors to give the illusion of an interior. When not in use, the structures are usually stripped of this dressing.

Mel Brooks' Blazing Saddles offers a rare look into the Warner Bros. backlot, with scenes spilling off the Laramie Street set into various stages and eventually out of Gate 3 onto Olive Avenue in Burbank, California. Television shows such as Moonlighting and It's Garry Shandling's Show also broke the fourth wall and gave audiences a peek of life on the other side of the camera.

...
Wikipedia