Doncaster, Charles County, Maryland

Doncaster Demonstration Forest is a state park in Charles County of the state Maryland. The park is 1,447 acres (586 ha) in size. It serves as an educational resource where a variety of silvicultural practices, forest best management practices and wildlife habitat management practices are implemented and studied. Recreational opportunities in Doncaster include hunting, hiking, horseback riding and mountain biking. It contains about 13 miles (21 km) of marked trails.

Chicamuxen is an unincorporated community in Charles County, Maryland, United States. Chicamuxen is located along Maryland Route 224, 1.5 miles (2.4 km) east of Linton Point.

Nanjemoy is a settlement along Maryland Route 6 in southwestern Charles County, Maryland, United States, and the surrounding large rural area more or less bounded by Nanjemoy Creek to the east and north, and the Potomac River to the south and west.

Chicamuxen Wildlife Management Area is a state Wildlife Management Area along Chickamuxen Creek near the Potomac River in Charles County, Maryland. The area includes a variety of landforms from marshland to rolling forest. The area provides duck and white-tailed deer habitat. The area was the location of an encampment for General Joseph Hooker's troops during the American Civil War.

Rison is an unincorporated community in Charles County, Maryland, United States. The Rison post office was established in 1905, but the area's residents are now part of the 20640 zip code area for nearby Indian Head. The community's elevation is 50 feet and it had a population of 50 in 1941. Revolutionary War General William Smallwood's home is preserved at Smallwood State Park in Rison along the Mattawoman Creek. Sweden Point Marina, site of major fishing tournaments, is located within the park, and used to be known as Sweetman's Landing. The site of historic Grinder's Wharf, in the mid-19th century an active steamship port for the Washington Steamship Lines, is off Upham Road in Rison. The residential subdivision Rison Acres was platted in 1973, the same year as the nearby Smallwood Estates subdivision. From 1955 to 2000, Robert Linkins, born in Rison, operated a one-man sawmill in Rison; the dirt road to his sawmill is now officially Linkins Road on Maryland State Route 224. Linkins died in 2008.

Mattawoman was an 18th-century plantation on Mattawoman Creek in Charles County, Maryland, United States.

Mallows Bay is a small bay on the Maryland side of the Potomac River in Charles County, Maryland, United States. The bay is the location of what is regarded as the "largest shipwreck fleet in the Western Hemisphere" and is described as a "ship graveyard."Mallows Bay was declared a National Marine Sanctuary on September 9, 2019.

The Mallows Bay–Potomac River National Marine Sanctuary is a National Marine Sanctuary in the United States located in the Potomac River in Charles County, Maryland. It is best known for the "Ghost Fleet," 118 historic shipwrecks in Mallows Bay in the sanctuary's northeast corner which is the largest shipwreck fleet in the Western Hemisphere. They are among more than 200 shipwrecks in the sanctuary, some of which date as far back as the American Revolutionary War and others to the American Civil War. In addition to shipwrecks, the sanctuary preserves historical sites related to Native Americans, some of them as much as 12,000 years old, as well as a lengthy span of United States history, including the American Revolutionary War, the American Civil War, steamboat and steamship actvity during the Industrial Era, and what was once an important Potomac River fishing industry. It also protects sites dating as far back as the 17th century related to African-American history, as well as an ecologically and biologically important area of the Potomac River and its Maryland shoreline that supports many species of plants and animals. Designated on September 3, 2019, the Mallows Bay–Potomac River National Marine Sanctuary was the 14th national marine sanctuary, the first in the Chesapeake Bay watershed, and the first one designated since the Thunder Bay National Marine Sanctuary in 2000.

Smallwood State Park is a public recreation and historic preservation area located on Mattawoman Creek near Marbury, Charles County, Maryland. The state park preserves Smallwood's Retreat, the plantation home of former Continental Army officer and Governor of Maryland, Major General William Smallwood. The park's 984 acres (398 ha) include a marina, boat ramps, picnicking facilities, campsites, cabins, trails, and nature center.

The Douglas Point Nuclear Power Plant was proposed in 1973 for a site on the Potomac River to the south of Washington, D.C. by the Potomac Electric Power Company (PEPCO). The proposed generating facility was to be located in Charles County, Maryland, about 30 miles (48 km) south of Washington, D.C. Two boiling water reactors of about 1150 megawatts were proposed, with projected in-service dates of 1981 and 1982. Two 450-foot (140 m) cooling towers were proposed, and water consumption was projected at 108,000 US gallons per minute (410,000 L/min). The project was set aside in the late 1970s. Opposition centered on the plant's effects on striped bass spawning grounds in the Potomac and consequent damage to the striped bass fishery in the Chesapeake Bay.The 1,270-acre (510 ha) site was purchased by the state of Maryland and the Bureau of Land Management and is operated as the Douglas Point State National Resources Management Area, part of the Maryland Department of Natural Resources' Nanjemoy Wildlife Management Area.

Mattawoman Creek is a 30.0-mile-long (48.3 km) coastal-plain tributary to the tidal Potomac River with a mouth at Indian Head, Maryland, 20 miles (32 km) downstream of Washington, D.C. It comprises a 23-mile (37 km) river flowing through Prince George's and Charles counties and a 7-mile (11 km) tidal-freshwater estuary in Charles County. About three-fourths of its 94-square-mile (240 km2) watershed lies in Charles County, with the remainder in Prince George's County immediately to the north.

Purse State Park is a former Maryland state park located on the Potomac River in Charles County that has been subsumed into the 1,365-acre (552 ha) Nanjemoy Wildlife Management Area. As the Purse Area, the former park is known for fossil hunting on the beaches of Wades Bay at the southern end of the Nanjemoy WMA. Fossil discoveries have included shark teeth and Cibicides.