Tham Muang On is located in Mae On District, Chiang Mai Province, not far from San Kamphaeng Hot Springs. It is a large cave that is a cavity under a limestone mountain. Inside Tham Muang On are stalactites and stalagmites that have formed naturally and “Phra That Nom Pha”, which is a stalagmite containing the hair of the Lord Buddha. It is considered a very strange and beautiful chedi because it is a natural object, not a man-made construction. Interesting points in Tham Muang On, besides Phra That Nom Pha, include the Stupa of Khru Ba Sriwichai located at the mouth of the cave, the Rishi Cave, stalactites and stalagmites in various shapes such as dinosaurs, stone cats, lion heads, dripping water from Nom Pha, Rishi’s chamber pots, stone turtles, Naga heads, thousand-tiered lotus, many-layered sand, million-year-old teak wood, various Buddha images inside the cave, the mysterious Phra Chao, Phra Kruana Chai Yas, and the Buddha sitting on a lotus. In addition, from the mouth of the cave, you can walk up more than 700 steps to pay homage to Luang Pho Than Chai and see the beautiful scenery.