This was in Nong Khiaw, Laos when I was there last in 2007.
Nong Khiaw travel guide - Wikitravel
Beautiful small town on both sides of the Ou river.
Wrote about the town in
Lew Lorton Photography | Adventures on the Road in Northern Laos
This is the river valley from the bridge over the Nam Ou.
On the right is where I stayed at the Nong Khiaw Riverside, owned by a Danish man and his Lao wife.
The view from my balcony
I wanted to visit the caves and my destination was one just below the tree line.
It was not an easy climb; the hillside has little dirt but lots of large, angular,
hard limestone boulders.
These were my 'guides' who were upset that I scraped my arm and insisted on chewing up leaves for a poultice.
Although the guide 'fee' was one dollar US, I gave them each a dollar and they were so elated that they showed up the next morning to carry my bag to the boat and wouldn't take anything.
We detoured on the way back and they showed me a hillside covered with nest of funnel spiders.
These are the karst cliffs along the river going up to Muang Sing, a village reachable only by water.