هويايكساي
هويايكساي
The Gibbon Experience is a once-in-a-lifetime opportunity - zip through the jungle in Northern Laos via a series of ziplines and spend the night sleeping in treehouses! If you're lucky, you can see or hear gibbons! Proceeds go to forest conservation. $320 for three-days / two-nights, two-days / one-night options are also available. Easy to get to from Chiang Rai or Luang Prabang.
Leaving Thailand for Laos via the crossing not far from Chiang Rai you take a quick boat ride across the Mekong River and you will find yourself in Hauy Xai.  

Probably the largest draw for visiting this town is the Gibbon Experience in Bokeo NP a couple hours away.  Sleep in a tree house (if the insanely loud insects don't keep you awake) and do some outstanding ziplining all while helping support conservation efforts in the area and the local villages.  More details---> http://turtlestravel.com/doing-lines-and-flying-high/