Suikinkutsu

Double suikinkutsu at Iwasaki Castle, Nisshin city, Aichi prefecture

A suikinkutsu (水琴窟, lit.'water koto cavern') is a type of Japanese garden ornament and music device. It consists of an upside down buried pot with a hole at the top. Water drips through the hole at the top onto a small pool of water inside of the pot, creating a pleasant splashing sound that rings inside of the pot similar to a bell or Japanese zither. It is usually built next to a traditional Japanese stone basin called chōzubachi, part of a tsukubai for washing hands before the Japanese tea ceremony.