For many, Thi Lor Su Waterfall is Thailand’s most impressive natural attraction, and though it requires some effort to get there, the experience of watching the waters thunder down a wide cliff is very rewarding.

Thi Lor Su is located in the Umphang Wildlife Sanctuary, a massive tract of virgin rainforest that is home to clouded leopards, serow (something between a goat and a deer) and several endangered bird species. Several ethnic hilltribes live in and around the sanctuary.

Though no-one would deny that Thi Lor Su is the country’s biggest waterfall, exactly how big it is remains rather vague. Estimates of its height are ‘about 200 meters’ and its width ‘about 400 meters’, though no precise figures are available. It certainly is an impressive sight when seen from the viewing platform below the falls, at the end of a delightful nature trail.

Visiting Thi Lor Su is all about timing. The best time is November, after the rains, when the skies are clear and it’s possible to clamber around the various pools at its base. Through the rain season (June-Oct), there’s so much water coming over the cliff that the viewing area is enveloped in spray and you can’t see the outline of the falls.

If you’re a confident driver and have a reliable 4WD vehicle, you can drive directly to the camp site at park headquarters from November to May, but most people (even Thai visitors who are in the great majority) prefer to take a tour which involves rafting and trekking to the campsite and staying overnight near the falls.

From Umphang, head north along H1090 to a turning to the west at the 161km marker. Take this turning and follow it to the entrance to the wildlife sanctuary, after which the road continues in very poor condition for another 25km. From June to November, the only way to get there is to join a tour.

  • What is it? Thailand’s most impressive natural attraction
  • When to go: November-December is best
  • Opening hours: 06:00-18:00 daily
  • Entrance fee: 200B to enter Umphang Wildlife Sanctuary if not with a tour
  • Where: in Umphang Wildlife Sanctuary, around 37km west of Umphang town