Zenkōji Temple is the centrepiece of Nagano, and one of the most important sites in Japanese Buddhism. It contains a secret Buddha statue claimed to be the first ever brought to Japan, and from the temple's establishment in the seventh century to this day, the devout still come to it on pilgrimage.
Of course, it has also become a major tourist destination. Perhaps most poular is the "underground passageway" beneath the main hall's Inner Sanctuary: a corridor drenched in utter darkness, narrow and with several right-angled turns, in which people can pay to stumble through in search for the 'Key to Paradise': a metal twirly-whirly thing which apparently conduces to enlightenment and spiritual awakening. Helpful hint: it's on the right wall, about halfway up, approximately three quarters of the way through the tunnel.
