Taian, the tea room at the temple Myōkian in Ōyamazaki, Kyoto Prefecture, has a seating area of only two tatami mats. With its anteroom and service space, the area is only about four and a half mats. It is a National Treasure.
According to the temple’s tradition, Sen no Rikyū built it in the camp of Hashiba Hideyoshi, and it was later taken down and moved to the temple. The attribution to Rikyū rests on that tradition.