Pyramids of Giza

This is the 2nd pyramid, which we were allowed to walk inside. When entering, one must crouch down as lowly as possible, to walk through a dark, tight narrow tunnel for about 30 feet. There is hardly any air going in/out of this tunnel, as it is so tight and narrow and bus loads of people are taking advantage of this once-in-a-lifetime opportunity, meaning the tunnel is clogged with one line drudging in and one line drudging out. I'd estimate the space to be 4 ft x 4 ft. After 30 feet or so, you can stand, but the air is still very thick and holy crap...hot isn't even the word. Then you turn around and come out, gasping for air like you just swam the English Channel in one breath.