Zenkō-ji善光寺
Founded, by tradition, in 644, and open to pilgrims of every sect. Its hidden Buddha is never shown. Below the National Treasure main hall (1707), the Okaidan is a pitch-dark passage where you feel along the wall for the "key to paradise". The morning service, O-asaji, is held at sunrise every day; stay in one of the 39 temple lodgings (shukubō) on the approach to see it.
The grounds are free. The inner sanctuary with the Okaidan is ¥800 and a set ticket for everything ¥1,500 (prices from April 2026). In 2027 the stand-in image goes on show for the Gokaichō, 4 April–19 June: book Nagano hotels early for spring 2027.