The Pak Ou caves are best known for the hundreds of miniature Buddhas that have been placed in them. There are two caves, both of which are accessible only by steps leading up from the landing jetty on the Mekong river.
The caves themselves are not really that spectacular to be honest, but the journey up the Mekong from Luang Prabang is quite scenic and tranquil. The caves are 25 kilometres away from Luang Prabang and the journey upstream will take you roughly two hours to complete. For those who are not so comfortable on a boat, there is the possibility to take a bus from Luang Prabang to Pak Ou village. By bus the journey only takes 45 minutes. However, even the locals agree that the road to Pak Ou is in such a bad state of repair that the longboat up the Mekong is probably the safer option. Besides, the village lies on the other side of the Mekong, so you will still need to take a ferry to cross from the village to the entrance of the cave.
All in all, even if you are not much of a culture vulture, I can highly recommend the trip up to the Pak Ou caves. If nothing else, than at least it makes for a very pleasant and relaxed way to spend an afternoon in the Luang Prabang province.