“Pi Tu Gro or Preto Lor Su Waterfall” is located on Doi Ma Muang Sam Muan in Um Phang Wildlife Sanctuary, Um Phang District, Tak province. It is a large waterfall that flows from the peak of Doi Ma Muang Sam Muan, with a height of about 500 meters. If you look in a high angle on the top of Doi Maung Sam Muen, you able to see the waterfalls flowing down the cliff, a long white path that flattens through the green mountains like a heart shape.