Photo: Thi Lor Su Waterfall.

Thi Lor Su Waterfall

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During rainy season, Thi Lor Su Waterfall thunders over 400-metre-long and 200-metre-tall vertical cliffs amid the dense jungle of Thailand’s far western frontier. In the dry months it transforms into an angelic set of falls with refreshing pools to swim in. Visiting Thi Lor Su requires planning, time and effort -- and it’s worth it.

Also spelt Thi Lo Su or Tee Law Su, among other ways, Thi Lor Su is a Karen word meaning "Black Waterfall," a name that seems odd after watching the whitewater cascade over tan and green cliffs. Often referred to as the "largest" waterfall in Thailand, tourism brochures claim that it’s the "sixth largest" and among the "six most beautiful" waterfalls in the world. We’ll just call it impressive.

Part of Thi Lor Su at the end of rainy season. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

Part of Thi Lor Su at the end of rainy season. Photo: David Luekens

Regardless of it’s ranking, Thi Lor Su is the highlight of Umphang Wildlife Sanctuary, where clouded leopards and tapirs roam beneath 1,300 different types of palms. Wild bananas attract elephants from the untamed wilderness, which joins several other protected areas to form one of mainland Southeast Asia’s largest contiguous forests.

After a multi-hour trip by four-wheel-drive vehicle and raft, if you choose, visitors arrive at sanctuary headquarters. From here it’s a relatively easy three-kilometre hike along a concrete walkway to the waterfall. Some of the old bamboo trees are as thick as the Burmese pythons that hang from them. Dipterocarp trees tower high above, with niches in the trunks that are large enough to host a tea party.

Into the green. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

Into the green. Photo: David Luekens

After pausing to listen to the wise old bamboo creak in the breeze, we came to a series of small waterfalls emptying into a wide lagoon. We then caught a first glimpse of Thi Lor Su’s upper tier through a break in the truck-size palms. Even at the end of dry season during a draught, the falls were breathtaking. Entire cliffs turn into a thundering sheet of whitewater during and just after the rainy months.

A large viewing platform where you can take in several tiers at once sits at the end of the main trail. A local guide told us that it’s not safe to go far beyond this point when the falls are at full volume towards the end of the rainy season.

Don't forget to look up. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

Don't forget to look up. Photo: David Luekens

An advantage of coming in the dry months is the ability to climb a series of steep trails leading up to the middle tiers, which get pummelled by water during the monsoon. We found the travertine pools to be as pretty and refreshing as any that we’ve come across at Erawan or Huai Mae Khamin waterfalls down in Kanchanaburi. For an hour we had the falls to ourselves.

It’s possible to camp under the shade of trees on a large field at sanctuary headquarters, but you must bring your own tent (tour companies can also arrange it for you) and pay a 30 baht fee. A small restaurant serves Thai food at limited hours from November 1 to April 30. We arrived in April ’16 to find dirty, spider-infested public bathrooms. We arrived to find a crew of rangers preparing machine guns for an expedition: illegal logging, wildlife poaching and drug smuggling occur in this remote patch of Thailand. Whether coming for an hour or staying for a week, all foreign visitors must pay a 200-baht entry fee.

A first glimpse from afar. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

A first glimpse from afar. Photo: David Luekens

The Thi Lor Su experience changes drastically from season to season. Expect quite a few Thai visitors on weekends and holidays, especially when the air is dry and the water flows powerfully just after the rainy season, from November to January. This is a good time for rafting on the nearby Mae Khlong River. A rafting trip will also take you past the lovely Thi Lor Jor Waterfall and a small hot spring.

In 2017, the road to Thi Lor Su was closed from June 1 to November 1; it was unclear if the closure would recur every year. Rafting should still be possible, and the river rapids would be a thrill at this time of year. The falls dry up in places and the rapids turn into quiet trickles later in the dry and hot months, from February into May.

You couldn't do this in rainy season. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

You couldn't do this in rainy season. Photo: David Luekens

Most visitors arrange transport or a package tour in Umphang town. Expect to pay between 1,500 and 2,500 baht to rent a pick-up truck with driver for a round trip, not including food or entrance fees. To find this option you’ll want to ask around among the locals in town rather than at resorts, which try to sell the pricier guided tours.

An inviting middle tier. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

An inviting middle tier. Photo: David Luekens

Resorts and tour companies offer day trips to Thi Lor Su starting at around 4,500 baht for two people and usually including a few hours of rafting before meeting up with a pick-up at Blood Camp for the final 13 kilometres to sanctuary headquarters. Thi Lor Su is also included on multi-day rafting and trekking trips out of Umphang.

It used to be possible for anyone with a four-wheel-drive vehicle to drive to the campsite on their own, but in late 2017 an independent traveller reported to us that all visitors must now pay for a local to transport them by pick-up truck.

If you want to attempt going on your own anyway, head north out of Umphang town and take a left (west) on Highway 1167. After around 10 kilometres, hang another left (south) on Highway 1288 and you’ll see the gate to Umphang Wildlife Sanctuary on the left after around six kilometres. The mostly dirt, 26-kilometre-long access road begins here, and we can’t overstate how rugged it is.

We could hang around here for a few days. Photo taken in or around Thi Lor Su Waterfall, Umphang, Thailand by David Luekens.

We could hang around here for a few days. Photo: David Luekens

Even when the road is dry, drivers will need to navigate over two-foot-deep rivets in the road, often while climbing up or rambling down hills with steep drops to one side and no barriers. Part of the road was sealed at one point, but these are now some of the roughest stretches due to badly eroded concrete. Driving this road in the rainy season would be like skiing through 26 kilometres of slop. At any time of year, the rangers do not allow visitors to attempt the road in a vehicle without four-wheel drive. While a motorised dirt bike could handle it, don’t expect to get here on a motor scooter or touring motorcycle.

The other option is to catch a Poeng Kloeng-bound songthaew at the hospital in Umphang town and hop off at the Umphang Wildlife Sanctuary gate, from where you could walk or hitch the 26 kilometres to the campsite. The songthaews depart roughly once an hour from 06:30 to 14:30 and can be caught going back to Umphang at the same place along Highway 1288. If you get stuck, a couple of cheap, privately owned resorts and campgrounds are located a kilometre or two north of the gate.

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Thi Lor Su Waterfall
Around 30km from Umphang

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