People have been climbing into theak Ou caves, high above the Mekong some 25km from Luang Prabang, for maybe a couple of thousand years.
They were used for the worship of the river spirit until Buddhism spread into Laos along the southern route from India.

And gradually, over the 60 decades, more than 4,000 Buddha images – mostly the standing Buddha of the Luang Prabang style – have been placed in them