The earliest known toilets in Japan date back about 1,300 years. Excavations have uncovered pits that were used as toilets, as well as more advanced toilets consisting of a ditch carrying water through part of the house to convey the waste outdoors. Since ancient times, there also existed toilets built over running streams. These types can be considered a primitive form of flush toilets.
Pit toilets came into widespread use over the following centuries. In the thirteenth century the Japanese, who were largely a farming people, began to use the waste taken out of these toilets as fertilizer.
Traditional Japanese toilets consist of a hole or basin in the floor and are not made to sit on but to squat over. Sewerages and seated toilets were introduced in Japan around the beginning of the twentieth century, but it was only after World War II that Western-style toilets began to spread on a major scale. Using human waste as fertilizer was banned for sanitary reasons, and flush toilets became common. Still, Western-style toilets did not fully replace Japanese-style ones, and even now the majority of toilets at train stations and other public facilities are the squatting type. This is probably largely because many Japanese prefer not to sit directly on toilets outside of the home, which they suspect may not be very clean.