Ota Ward in Tokyo was originally divided into Omori Ward and Kamata Ward, but merged in 1947 to form Ota Ward. As the area is blessed with both the sea and rivers, seaweed farming, a seafood product, was popular in the past, but since the Taisho era, many factories have been built, and it is now the Keihin Industrial Zone. Ota Ward's attractions include Haneda Airport and Heiwajima Park. Haneda Airport is used by many people as a departure and arrival airport for domestic flights and international charter flights. In recent years, it has also become a hub airport and is open 24 hours a day. Heiwajima Park also has a pool, making it a recommended place to visit in the summer.