I went to a cave while I was there, the usual stalactites and stalagmites. But very nice and cool on a hot day. Damp. And interesting graffiti from 100 years ago when it was discovered, mostly in french and some in Chinese. It had been discovered, and then lost, and then used by the viet kong to hide people and weapons from American detection. I haven't been to a cave for a while, and I enjoyed it. Touristy as hell, of course, but occasionally I was actually alone in a section, so it wasn't objectionably crowded.