city, Saitama ken (prefecture), Honshu, Japan. Ageo lies on the terrace between the Ara River (west) and the Ayase River (east). A former post town between Tokyo and Maebashi, it was connected to Tokyo (25 miles 【40 km】 southeast) in 1883. Ageo remained the market centre of the neighbouring agricultural region until 1955, when machinery, rubber, and metallurgy industries were developed in the city. Pop. (2005) 220,232.