From Wikipedia: Near Pak Ou (the mouth of the Ou river), the Tham Ting (lower cave) and the Tham Theung (upper cave) are caves overlooking the Mekong River. The caves are noted for their miniature Buddha sculptures. Hundreds of very small and mostly damaged wooden Buddhist figures are laid out over the wall shelves. They take many different positions, including meditation, teaching, peace, rain, and reclining (nirvana).
I didn’t fully enjoy my trip to Pak Ou Caves. I booked a half-day trip through a travel agent in Luang Prabang (180,000 kip total for this trip and a half-day Kuang Si Falls trip). There was an extra admission fee of 20,000 kip. The lower cave was definitely awesome but the boat trip there and back was simply too long… Over three hours in an uncomfortable wooden chair. (Even the massage I got afterwards couldn’t heal my back pain!) I didn’t hike to the upper cave as we didn’t have much time there and I was too lazy! We also stopped at a whiskey village along the way. As I don’t drink whiskey, this was not appealing to me. Also we had to climb up and down very slippery, muddy stairs. Wear tennis shoes!