A region of ancient cities to the west (sai) of the mountain barrier (kan) near Mount Fuji, the birthplace of the earliest Japanese state and one of Japan's traditional cultural areas. It is an area of historically dense population that until well into the 20th century was the most industrialized and economically advanced part of Japan. It was an early medieval administrative district of west-central Japan, roughly the same as the modern Kinki district. The Keihanshin Industrial Zone corresponds to the Kansai.