Landon Lake

Deerfield Township, one of the eleven townships of Warren County, Ohio, United States, is located in the southwest corner of the county. The most urbanized of the eleven, it had 36,059 people in the 2010 census. Before that, it had 25,515 people in the 2000 census and 26,359 in the 1990 census. (The drop from 1990 to 2000 is because the city of Mason, which was included in the 1990 figures, withdrew from the township in February 1997.) Until it was annexed into Mason in 1997, Kings Island amusement park was in the township.

Landen is a census-designated place (CDP) in Deerfield Township, Warren County, Ohio, United States. The population was 12,766 at the 2000 census. It is located around Columbia Road and Montgomery Road in the southeastern part of the township. It surrounds Twenty Mile Stand and near Fosters.Landen was named after Theodophilus James Landen, an early Ohio settler who owned the farmland surrounding Twenty Mile Stand.