#1 · 250 m drop
Thi Lo Su Falls
Umphang · Tak · Thailand
If you've been collecting waterfalls the way some people collect stamps, Thi Lo Su needs to be on your list — but fair warning, this one doesn't come easy.
Tucked deep inside the Umphang Wildlife Sanctuary in Tak province, Thi Lo Su is one of those "the road is long, but wow, it's worth it" kind of places. According to the Tourism Authority of Thailand, it's a limestone waterfall standing around 300 meters tall and stretching roughly 500 meters wide — the scale is honestly hard to process until you're standing in front of it. From a distance it doesn't even look like a single waterfall, it looks like the whole mountainside is flowing.
You won't get there by just parking and walking up to it. There's a stretch of mountain road first, then forest, then a hike, and the falls only show up at the end of all that. Nothing along the way is built for tourists. No paved viewing platform, no gift shop halfway through. It's still pretty much what it's always been.