Fermented black soybeans are the oldest-known food made from soybeans. In 165 BCE, they were placed, clearly marked, in Han Tomb No. 1 at Mawangdui Tomb Site in South Central China. The tomb was sealed about 165 BCE and was first opened in 1972.[1][page needed] The high-ranking woman to whom the undisturbed tomb belonged was probably the wife of the first Marquis of Tai. [citation needed]