When you are dining outside in a restaurant, sometimes, you can notice that the washroom of the restaurant are uniquely build. There is one washroom where there are trees and garden inside. I cannot remember where is it located. However, I never see a stone sink before. Is it because it is not that popular over here? Or is it expensive or not suitable to use it? Maybe for people who like the stone sink, they can install it in their home instead. It should be unique and nice.