Mount Tsukuba holds a distinction that no other Japanese mountain can claim: it appears more frequently in the Man'yoshu, Japan's oldest surviving poetry anthology compiled around 1,300 years ago, than any other peak in the country. The poets of the Nara period looked east from the capital and saw in Tsukuba's twin silhouette a symbol of conjugal union, of opposing forces held in balance. The mountain is described in the Man'yoshu as "the inheritance of man from the age of gods," a phrase that captures the deep antiquity the Japanese have always attached to this place. At only 877 meters, Tsukuba is no alpine giant -- it rises from the flat Kanto plain like a gentle double hump, visible for miles across the rice paddies and research parks of modern Ibaraki. Its power was never about height. It was about meaning.

The shrine's architecture mirrors the mountain's duality. The main sanctuaries sit on the twin summits: Nantai-san at 871 meters enshrines Izanagi, the male creator, while Nyotai-san at 877 meters enshrines Izanami, the female creator. Lower on the mountain, near the cable car station, stand the hall of worship and the broader shrine precincts where most visitors begin their ascent. Four auxiliary shrines, called sessha, are positioned along the Shirakumo Bridge trail that winds between the summits, each enshrining one of the child gods born of Izanagi and Izanami's union. Beyond these, at least 100 subordinate shrines are scattered across the mountain's slopes. The shrine holds the Beppyo designation from the Association of Shinto Shrines, marking it as a site of special significance, and it remains an Important Cultural Property of Ibaraki Prefecture.

Tsukubasan Shrine's main festivals take place on April 1 and November 1, and they operate as mirror images of each other. In April, an omikoshi -- a portable shrine carried on the shoulders of bearers -- holds a child god and is escorted up the mountain in a procession that follows the old pilgrimage trails through forests of cedar and beech. The crowd climbs with the shrine, the route steepening as it nears the summit sanctuaries. In November, the procession reverses: the omikoshi descends, carried back down to the lower precincts. This seasonal rhythm of ascent and descent reflects the agricultural calendar that once governed life on the Kanto plain, the spring climb a prayer for growth and the autumn return a thanksgiving for harvest. The festivals draw worshippers seeking blessings for marriages, safe families, and bountiful crops.

Modern visitors can reach the summits by foot, by the Tsukuba Cable Car funicular that climbs from Miyawaki Station to the peak of Nantai-san, or by the ropeway that ascends from Tsutsujigaoka Station to Nyotai-san. From the top, the views explain why poets wrote about this mountain for centuries. Nantai-san looks out across the vast Kanto Plain, a geometric patchwork of rice fields and suburban development stretching to the horizon. On clear days, Nyotai-san offers a view southwest to Mount Fuji itself -- the western half of the old proverb made visible. Below, the city of Tsukuba spreads out, home to Japan's premier science research cluster, a thoroughly modern place built in the shadow of a mountain whose religious significance predates recorded history. The contrast between the particle accelerators and research institutes at the mountain's base and the 3,000-year-old shrine on its slopes is pure Japan: the ancient and the cutting-edge, side by side, neither diminishing the other.