In 859, during the first year of the Jogan Era, the Tendai Buddhist monk Ennin founded a temple called Ryozen-ji on the mountain's slopes. The name Ryozen was adapted from Mount Ryojusen -- known in Sanskrit as Gridhakuta, or Vulture Peak -- the mountain in India where the Buddha is said to have delivered the Lotus Sutra. Ennin chose the site for its remoteness and its spiritual power; the mountain was already regarded as sacred and had become a center for Shugendo, the ancient Japanese practice of mountain asceticism that blends Buddhism, Shinto, and folk belief. Practitioners climbed through mist and basalt to seek enlightenment in the physical ordeal of the ascent itself.

Nearly five centuries after Ennin's temple was founded, the mountain became a fortress. In 1337, during the turbulent Nanbokucho period -- Japan's war between Northern and Southern imperial courts -- Kitabatake Akiie, the young governor of Mutsu Province and a champion of the Southern Court, fortified the temple grounds and established Ryozen Castle. He set up the Mutsu provincial government there in the name of Prince Noriyoshi. From this basalt stronghold, Akiie launched a military campaign southward, fighting several battles before being killed on May 22, 1338, at the age of twenty-one. Ryozen Castle survived its builder by nine years before it was destroyed by the Northern Court's army. Today, the Gomadan area on the hiking trail marks the castle's entrance -- a low-hanging rock you must duck beneath before emerging into the broad, flat clearing where Buddhist rituals and military councils once took place.

The hiking trail up Mount Ryozen passes through a gallery of volcanic geology and folklore. At Hojudai, a cliff-top viewpoint, the Abukuma and Azuma Mountain Ranges stretch to the horizon. At Kokushisawa, a rock face rises at a near-perfect right angle from the valley floor, reached by ladders bolted to the stone. Then comes the Tengu no Sumo Jo -- the tengu wrestling hall -- that flat, westward-jutting rock where the mountain spirits are said to compete. The tengu of Japanese mythology are powerful, shape-shifting creatures associated with mountains and martial arts, and Mount Ryozen's volcanic crags make a fitting home for such beings. The trail passes through all of this in a single ascent, weaving between sacred sites and sheer drops.

Mount Ryozen is part of the basalt volcanic plateau of the Abukuma Highlands, and its geology creates a dramatic canvas for what the mountain is perhaps most famous for: autumn foliage. Each October and November, the maples and deciduous trees that cling to the basalt cliffs erupt in shades of crimson, orange, and gold, framing the dark volcanic rock in living fire. The mountain was selected as one of the 100 Landscapes of Japan in a contest sponsored by the Tokyo Nichi Nichi Shimbun and Osaka Mainichi Shimbun, and it holds national recognition as a Place of Scenic Beauty from the Agency for Cultural Affairs. From the peak, where the ruins of Ryozen Castle lie beneath the grass, the view stretches across the highlands in every direction -- and on clear days, all the way to the Pacific coast where Soma and Minamisoma meet the sea.