東京湾
The Tokyo Bay Aqua-Line is a bridge–tunnel combination across Tokyo Bay in Japan. It connects the city of Kawasaki in Kanagawa Prefecture with the city of Kisarazu in Chiba Prefecture. With an overall length of , it includes a bridge and tunnel underneath the bay—which is the longest underwater tunnel for cars in the world. Drawbridges were impractical here because Tokyo Bay is too active a sea lane.