A Suikinkutsu (water koto cave) is a type of Japanese garden decoration that produces koto-like sounds from dripping water.
Source: Free encyclopedia "Wikipedia"
Structurally, a jar with a small hole in its bottom is buried upside down in the ground, and its base is solidified with clay or similar material to collect water. A chozubachi (water basin) is typically placed above it, from which water flows down and drips through the jar's hole. The sound produced at that time resonates inside the jar, creating a koto-like sound.
Traditional Suikinkutsu are often installed alongside a tsukubai (low stone basin) in front of a tea room.
When water flows, it produces a lovely kiloron-keen..... sound (~_~) 