Zeniarai Benten Shrine is a unique Shinto shrine located inside a cave on a hillside. According to tradition, washing your money in the sacred spring water will cause it to multiply. The shrine was founded in 1185 by Minamoto no Yoritomo after he had a vision. Visitors enter through a rock tunnel and the main cave contains spring water where people wash their coins and bills. The ritual involves buying incense and a candle, praying, then washing money in small baskets provided.