S P O T ／ SPOT-105

Otainai Seikoen and Tainai Shrine

御胎内清宏園・胎内神社おたいないせいこうえん・たいないじんじゃ

On the lava skirts of Mount Fuji's eastern flank, an approximately sixty-eight-meter lava tube has been read since at least the Edo period as the interior of a human body and consecrated as a shrine. Visitors enter Otainai Seikoen, a small park built around the tube, and then crawl, stoop, and squeeze through the tunnel as if traversing a womb, emerging on the far side where the Tainai Shrine — long associated with safe childbirth — is enshrined. The site is one of several 'womb caves' scattered across the foot of Fuji, where natural lava geography and folk beliefs about rebirth and fertility have layered onto each other. Closed-toe shoes and a willingness to get a little muddy are non-negotiable.