Sayama (狭山市 Sayama-shi?), formerly known as Irumagawa, is a city located in Saitama Prefecture, Japan. Sayama translates as "sitting on a mountain”. The city was founded on July 1, 1954. As of October 1, 2010, the city has an estimated population of 157,453 and a population density of 3,210.71 persons per km2. The total area is 49.04 km2. The current Mayor is Yukinari Nakagawa (仲川幸成), who was elected in 2003.