The waterfall at kilometre 11 or Tad Lak Sip-et is nothing to write home about but it's a pleasant enough spot to come and have a picnic with the locals.
They flock there to grill fish and have a swim, especially on the weekends and holidays.
The waterfall isn't that powerful, making swimming here safe and fun. Women should wear a sarong over their bathers or go in clothed. You'll need your own wheels or hire a tuk-tuk to get here. As the name suggests, it's 11 kilometres from Udomxai, on the road to Luang Prabang.
By Cindy Fan.
The Travelfish newsletter is sent out every Monday and is jammed full of free advice for travel in Southeast Asia. You can see past issues here.