Castlewood Map
Castlewood is a city in Hamlin County, South Dakota, United States. It is part of the Watertown, South Dakota Micropolitan Statistical Area. The population was 627 at the 2010 census.
Castlewood is located at 44°43?24?N 97°1?46?W / 44.72333°N 97.02944°W / 44.72333; -97.02944 (44.723262, -97.029505), along the Big Sioux River.
According to the United States Census Bureau, the city has a total area of 1.1 square miles (3.0 km²), all of it land.
Nearby cities include Estelline, Watertown, Lake Norden, Goodwin, Clear Lake.