Kawasaki (Kawasaki-shi) is a city located in Kanagawa, Japan. It is sandwiched between Tokyo and Yokohama to form part of Greater Tokyo, the most populous urban area on earth. It is also the most populous city in Japan without its own city subway system, however, the city is heavily rail based. The region where Kawasaki lies was originally part of Musashi Province, or Tokyo region (as opposed to Sagami associated with Kanagawa), as evidenced by the Nambu Line.