Three Mountains of Dewa (Dewa Sanzan)
Mount Haguro, Mount Gassan, and Mount Yudono are known collectively as the Three Mountains of Dewa, and are visited by many people as a sacred place of the Shugendo religion. It is said that a tour of these three mountains is a "life-changing trip". You can also find the highest number of "Sokushinbutsu" in Japan. These are a kind of Buddhist mummy, formed from ascetic monks who, in order to become Buddhas, entered ancient stone chambers in the ground while still alive and were mummified.