Located in the northwestern part of Chiba Prefecture, Inba-numa is a freshwater lake consisting of two swamps, namely Kita-Inba-numa and Nishi-Inba-numa, connected by a quick waterway. It has spread across many municipalities such as Sakura and Inzai, and has been used for agriculture and fishing since ancient times. In recent years, reclamation has progressed and residential land has been developed around the swamp, but the rural landscape is still visible and the rich nature remains. Many people visit fishing because there are many fish such as carp and crucian carp in the swamp, and cycling roads and promenades are also maintained along the lakefront. There are parks such as Sakura Hometown Square in Nishi Inba-numa, and there are a variety of events by each municipality, mainly in the swamp.