"Small boxes with dead bolted doors about 10 feet off the ground. Wall of a cinema."
A: "They are almost certainly access for speakers or lighting. If you stop to think about what would be involved in using a lift inside you can see why the access is outside. My guess is that this is an older theater retrofitted or perhaps a partition wall was demolished. You’d prefer to have an access space there, but if you can’t–because it’s an outside wall–you have to do this."