Calamus Swamp is a 19-acre (0.077 km2) public preserve located 1.5 miles (2.4 km) from Circleville in Pickaway County, Ohio, United States. It has a natural kettle lake/wetland and is owned by the Columbus Audubon, the local chapter of Audubon.
Calamus Swamp includes the only known kettle lake in Central Ohio that is naturally vegetated and undisturbed. The kettle lake was made in the last ice age by the glacier that covered 2/3 of Ohio. When Ada May Burke and Sally V. May got the land, they donated it to Columbus Audubon, who then made it into a public preserve.
According to the Columbus Audubon website, Calamus Swamp has a unique plant community. Because of the moist soil, trees such as the American Elm, Green Ash and, in places, Red and Silver maples make up the swamp forest.
Calamus Swamp has a wide range of birds and animals: