The passageways in all of the pyramids are fairly well lit. Floating orb images appeared on several of the pictures. They could be Spirit or something in the film. Spirit can be felt in the passageways and chambers but they were not necessarily of the Pharaohs. The chambers have no ventilation and are very hot.
Some chambers are easy to access - while others are a bit more difficult.
Most tourist could climb down the chambers. Though certain Pharaohs were supposedly buried in certain chambers - you know that the whereabouts of the mummies have never been found. For it is only the spirit that is real. The rest is illusion. Of course we know that isn't true.