Wada House: Outhouse
The shed-like building in front of the entrance to the Wada House is the family outhouse, or lavatory. Notably spacious, it is of a type found attached to only the largest gassho-style houses in Shirakawa-go. The building has three rooms: horses were kept in one of these, and the other two were toilet booths used by the Wada family. One of the booths has been converted into a storeroom but the other remains in its original form. The toilet consists of a large wooden barrel with a few planks placed across it for the user to stand or sit on. These facilities were intended mainly for solid waste, as the house also had an indoor latrine from which urine was led into a pit underneath the floor. The pit was used to produce saltpeter (potassium nitrate), an essential ingredient in gunpowder, and was filled with materials including straw, soil, mugwort, and silkworm droppings. Human urine facilitated the fermentation of this mixture.