The biggest limestone cave in Asia. I don’t know whether that makes it the biggest cave of any kind or whether you can get bigger granite ones or whatever but it was a pretty impressive hole in the side of a mountain nevertheless.
There didn’t seem to be much in the way of stalactities or stalagmites but the caverns were massive and the formations were beautifully weird like some alien spaceship or an inside out Cappodocia. And the English language should surely come up with a special word to describe that feeling you get when wobbling around on a rope-bridge over a chasm that is too dark and deep to measure.