A chōzuya or temizuya (手水舎?) is a Shinto water ablution pavilion for a ceremonial purification rite known as temizu.
Water-filled basins, called chōzubachi, are used by worshipers for washing their left hands, right hands, mouth and finally the handle of the water ladle to purify themselves before approaching the main Shinto shrine or shaden (Japanese: 社殿). This symbolic purification is normal before worship and all manned shrines have this facility, as well as many Buddhist temples and some new religious houses of worship. The temizuya is usually an open area where clear water fills one or various stone basins. Wooden dippers are usually available to worshipers.
Originally, this purification was done at a spring, stream or seashore and this is still considered the ideal. Worshipers at the Inner Shrine at Ise still use this traditional way of ablution.

via Wikipedia