御茶水 (Ochamizu) refers to cold water that has been drawn from a well or spring, and then boiled and cooled to provide a refreshing and hydrating drink. It is often served in traditional Japanese tea ceremonies to cleanse the palate before drinking tea, and is also commonly consumed during the hot summer months to cool down and rehydrate the body. In addition to being a popular beverage, Ochamizu is also known for its purity and high quality, as the water is sourced from natural springs and wells that are carefully selected for their mineral content and taste.