Introduction to the four-color water: The four-color water is located in front of Bei Niujiaoji in Tongjiang County. It is formed by the confluence of Nuo water, sulfur water, and Niujiaji cave water. It is black and white, clear and turbid, and has four colors. , hence the name. Whenever the Nuo water is clear and green, the water in the Cave is turbid and orange; conversely, when the river rises and floods, the cave water is clear and green; the sulfur water turns from black to white. One water has four colors, and so does the four seasons. Because the sulfur water changes obviously from black to white and has a strong smell, it is commonly known as "stinky water" and also known as "color-changing spring".