Do you know the origin of the term "They're filming on the lot"?
Back in the 1910s, the majority of filmmakers did not have studios as we know today. Generally they'd rent a few buildings for offices, props, wardrobe and possibly a few dressing rooms.
A film company would rent a near-by empty lot. (At that time, L.A./Hollywood area had wide open spaces, excepting downtown LA.)
They would build their sets on this lot, serving as its studio, taking advantage of the natural sunlight. (If the sun was to harsh, a screen of muslin would be pulled over the set to diffuse the sunlight.) Sometimes budget-tight films just set up in a empty lot without permission & hoped they wouldn't get caught.
If someone came by the production offices and asked where everyone was, they'd reply "They're shooting on the lot."
This is how the term became part of our industry vernacular.
