"…I switch off my headlamp just to feel the depth of the darkness. At first there is nothing. But then, as my pupils adjust, I’m surprised to make out a faint, ghostly light ahead. I pick my way through the rubble, almost running from excitement, rocks scattering beneath my feet and echoing in the invisible chamber. Traversing up a steep slope, I turn a ridge as if on a mountainside and am stopped in my tracks.
An enormous shaft of sunlight plunges into the cave like a waterfall. The hole in the ceiling through which the light cascades is unbelievably large, at least 300 feet across. The light, penetrating deep into the cave, reveals for the first time the mind-blowing proportions of Hang Son Doong. The passage is perhaps 300 feet wide, the ceiling nearly 800 feet tall: room enough for an entire New York City block of 40-story buildings. There are actually wispy clouds up near the ceiling.…"
Story by Mark Jenkins for National Geographic
(Picked up today on BoingBoing)