Chiang Khong is set on the far northern Thai border, straight across the swirling waters of the Mekong River from the Lao town of Huay Xai. Chiang Khong is primarily known for being one of the more popular border crossings for backpackers and independent travellers travelling to and/or from Laos.
(http://www.travelfish.org/location/thailand/northern_thailand/chiang_rai/chiang_khong)