Tat Kuang Si park is a wonderful spot for a hike.
The water has an amazing blue color that seems almost fake in photos but is really the color of these photos. The blue is due to dissolved copper.
The Kuang Si waterfalls are about 30 km outside of Luang Prabang. You can rent a open back pickup for about $30 (really I forget I think it was about that amount though) for the trip or you can join a tour group (easy to arrange at many guest houses and travel agents all over Luang Prabang).
The scenery in Yangshuo (near Guilin), China was great. Floating down the river on bamboo rafts was wonderful. I floated down a second river the day after the first because I liked it so much.
I was happy with, Amy, my guide for Yangshuo. Her son was the driver. I don’t usually use guides but for China I am glad I did (it is very difficult to get by compared to Cambodia, Indonesia, Malaysia, Thailand, etc.). Th costs were much more than those places without a guide but the charges were reasonable. If you can afford it, I recommend getting a guide and Amy was good.