In 766 AD, the Buddhist monk Shodo Shonin climbed into the mountains north of the Kanto Plain and founded a hermitage along the Daiya River. Shodo had been born in 735, and by the time he reached the remote heights of what would become Nikko, he was a seasoned ascetic drawn to places where the natural world felt close to the divine. The isolation was the point. Deep in the mountains of central Honshu, far from the imperial courts and busy monasteries of the lowlands, the site attracted other monks seeking the same solitude. Over the centuries, the hermitage grew into a major temple complex affiliated with the Tendai school of Buddhism -- a tradition that emphasized rigorous meditation, esoteric ritual, and training in remote mountain settings. Rinno-ji remains an important center for Tendai ascetic practice today, more than 1,250 years after Shodo first walked these slopes.

The Sanbutsudo -- the Hall of Three Buddhas -- is the largest building at Rinno-ji and the theological heart of the complex. Inside stand three massive gold-lacquered wooden statues, each 7.5 meters tall. At the center sits Amida Nyorai, the Buddha of the Western Pure Land, representing Mount Nantai. To one side stands Senju Kannon, the Thousand-Armed Kannon, embodiment of Mount Nyoho. To the other rises Bato Kannon, the Horse-Headed Kannon, corresponding to Mount Taro. These are not arbitrary pairings. The three peaks above Nikko were objects of Shinto worship long before Buddhism arrived, and the Sanbutsudo statues represent the syncretic theology that fused both traditions: each mountain kami has a Buddhist manifestation, each Buddha has a mountain home. The same three deities are enshrined in Shinto form at nearby Futarasan Shrine, creating a theological mirror between temple and shrine that visitors walk between to this day. A decade-long renovation of the Sanbutsudo was completed in 2019, restoring the hall to its full splendor.

Rinno-ji administers one of Nikko's most elegant sacred buildings: the Taiyuin mausoleum, final resting place of Tokugawa Iemitsu, the third Tokugawa shogun who ruled from 1623 to 1651. Iemitsu had expanded his grandfather Ieyasu's shrine at Tosho-gu into the lavish complex visitors see today, and when he died, his own mausoleum was built on the same mountainside -- deliberately smaller and facing toward Tosho-gu as a gesture of eternal deference to the founder. The Taiyuin complex, comprising the Honden, Ainoma, and Haiden structures, is designated a National Treasure of Japan. In total, 38 buildings of Rinno-ji are included in the UNESCO World Heritage listing of the Shrines and Temples of Nikko, recognized in 1999. One structure is a National Treasure and 37 are Important Cultural Properties -- a concentration of protected architecture that reflects the temple's central role in a sacred landscape spanning both Buddhist and Shinto traditions.

Deep in Rinno-ji's Great Goma Hall resides Chinjo Yasha, a fierce protective deity classified as a yaksha -- a class of nature spirits absorbed into Buddhist cosmology. Chinjo Yasha is understood as a manifestation of Vaisravana, one of the Four Heavenly Kings who guard the cardinal directions in Buddhist theology. The deity serves as a protector of the state, and the ritual tradition surrounding Chinjo Yasha traces back to Saicho, the ninth-century founder of the Tendai school in Japan. What makes this figure extraordinary is its secrecy: Chinjo Yasha is revealed to the public only once every nine years, in a year determined by Nine Star Astrology. The most recent public unveiling was on February 3, 2023. For the other eight years, the deity remains hidden -- a reminder that some sacred things are not meant for constant viewing, that the power of a place can lie in what it chooses to conceal.