The Arakawa River(荒川,Ara-kawa?) is one of the principal rivers flowing through Tokyo, the capital city of Japan. The point of origin is on Mount Kobushi in Saitama Prefecture, and the Arakawa River empties into Tokyo Bay, spanning 173 kilometers (107 mi). The drainage basin covers 2,940 square kilometers (1,140 sq mi). The widest section of the river ranges 2,537 meters (8,323 ft) at around Gonari Bridge and ranks number one in the nation.