Seyaku-in was a facility that Prince Shotoku, based on the Buddhist philosophy of mercy, had allegedly erected within the premises of Shitenno-ji Temple, where medical herbs were cultivated to relieve people who suffered from injuries or diseases.
施薬院（せやくいん）は、聖徳太子が仏教の慈悲の思想に基づき、その地に薬草を栽培し、怪我や病気で苦しむ人を救うために四天王寺内に作ったと言われる施設。