Namtok Thi Lo Su waterfall located in the Umphang Wildlife Sanctuary, Umphang district, Tak province is the Thailand’s most beautiful waterfall. In Karen language, which is spoken by a minority in Thailand, ‘Thi Lo Su’ means “giant” or “black waterfall”. It is located on the top of big limestone mountains at 900 meters above sea level spilling water onto three main waterfall landings or levels from a height of 300 meters with a width of 500 meters. Upon entering the reserve, the walkway starts with a surrounding of grasslands and then slowly transforms into looming trees. There, the camping spot can be seen, and a 1.5 km-pathway surrounded by mixed deciduous forest and bamboo grove leads visitors to their destination. During the walk, visitors will find plant species labels providing a variety of fascinating information and at the end of the path is a viewing platform of 300 m high and 500 m wide waterfall running down from a giant limestone cliff. There are three main waterfall landings or levels, so each ascent will be worth the effort. The first level (when facing the waterfall) is the largest and most beautiful of all levels with many falls over it. At the second level, the waterfall above is narrower and higher. While the third level is overlooking the second level with more water, although slightly having lower cliff. All in all, it is a very scenic place, surrounded by lush green forest and an abundance of nature. On the other side of the waterfall, a large viewing platform where you can take in several tiers at once sits at the end of the main trail. To leave the waterfall, it will take one hour back to the main entrance.
During the wet season from June to October Thi Lor Su is spectacular. Visitors can travel to Thi Lor Su waterfall by taking inflatable boat from Mae Klong River through Um Phang district. There is an exciting river leading visitor to the destination providing unique views along the way. During the journey, visitor will pass hot spring and approach “Namtok Sai Rung”. The highlight is a strikingly beautiful rainbow when the sun shines on it. With luscious and beautiful scenic jungle for visitors to admire along the way, the beauty of Pa Leud Cliff, Pa Bong Cliff, and Pa Hwo cliff will also be appreciated. After taking approximately three amazing hours of boat trip, visitors will continue enjoying their 9 kilometer-trekking to the camping area in Umphang Wildlife Sanctuary. No vehicles are allowed in the area. Visitors will adventurously have fun walking on slippery slopes and steep hills until reaching the destination. They will have time to take a break before taking another 1.5 km trekking to finally reach Thi Lor Su waterfall. During this period, due to large amount of rainfall, the water stream and fall gets larger and bigger making the waterfall even more beautiful while the forest turns green and river water changes into light brown. Trekkers who love adventure travel will definitely be satisfied.