The peak season for visiting tourists is during the months of December and January. At this time, the water level is still high to appreciate the falls, and the access road is open to the public. The water current is at its strongest between June to November, and the waterfall is at its most fascinating appearance. However, it is also the rainy season and the terrain is more dangerous for trekking. The local government discourages visits during these times though, so they close off the access road.
Spanning the forest of Umphang Wildlife Sanctuary in Thailand, the Thi Lo Su is a massive waterfall that spills water from a height of 250 meters. It is even taller than the Niagara Falls and is the largest in Thailand, and sixth in the world, with a width of 450 meters. It is spectacular because of its many cascades, and its vast stretch of powerful waterfalls that only an aerial photo can capture all of it. The sanctuary is a UNESCO World Heritage Site, located in Tak Province (Wikipedia Article) in Northern Thailand, which connects with other three major national parks and virgin forests: the Khlong Lan National Park (Wikipedia Article), Mae Wong National Park, Thung Yai Naresuan Wildlife Sanctuary, and Huai Kha Kaeng Wildlife Sanctuary. All of them combined form the largest wildlife sanctuary in Thailand.
Thi Lo Su is Thai for “loud waterfall”, with ‘Su’ being the word that stands for “loud”. It is also spelled in different forms: Thee Lor Sue, The Lor Sue, Thee Lor Sue, or Te-law-zue. In Karen language, which is spoken by a minority in Thailand, ‘Thi Lo Su’ means “giant” or “black waterfall”. It comes from the stream, up in the mountain called ‘Huai Klotho’, before plunging to the Umphang Forest, through large limestone rocks. Its various levels also give tourists various pools to swim in and the cave behind the waterfall is another opportunity for adventure.
Upon entering the sanctuary, the walkway starts with a surrounding of grasslands and then slowly transforms into looming trees. There, the entrance gate can be seen, and upon paying the entrance fee, a concrete and stone pathway leads visitors to their destination. At the end of the path is a viewing platform that has the best angle for taking photos.
There are three main waterfall landings or levels, so each ascent will be worth the effort. The first level has small pools of water for bathing with four falls over it. Swimming is prohibited at the second level as the water is deeper, and the waterfall above is narrower and higher. The third level is overlooking the second level, and there are sedimentary rocks under the water to sit and walk on. Some tourists cross the span of the waterfall and back.