Marden House

Little Falls Branch, a 3.8-mile-long (6.1 km) tributary stream of the Potomac River, is located in Montgomery County, Maryland. In the 19th century, the stream was also called Powder Mill Branch. It drains portions of Bethesda, Somerset, Friendship Heights, and Washington, D.C., flows under the Chesapeake and Ohio Canal (C&O), and empties into the Potomac at Little Falls rapids, which marks the upper end of the tidal Potomac.

Fort Marcy was a Union fortification protecting Washington, D.C. during the American Civil War. Its remains are now administered by the National Park Service as part of the George Washington Memorial Parkway in Fairfax County, Virginia.

Pimmit Run is a 7.8-mile-long (12.6 km) stream in northern Virginia that runs from Fairfax County to the Potomac River at Chain Bridge in the Arlingwood neighborhood of Arlington.

The Washington Aqueduct is an aqueduct that provides the public water supply system serving Washington, D.C., and parts of its suburbs, using water from the Potomac River. One of the first major aqueduct projects in the United States, the aqueduct was commissioned by the U.S. Congress in 1852, and construction began in 1853 under the supervision of Montgomery C. Meigs and the U.S. Army Corps of Engineers. Portions of the aqueduct went online on January 3, 1859, and the full pipeline began operating in 1864.: 68 The system is owned and operated by the U.S. Army Corps of Engineers and has been in continuous use ever since. It is listed as a National Historic Landmark and the Union Arch Bridge, where it is listed as a Historic Civil Engineering Landmark.

The Chain Bridge is a viaduct which crosses the Potomac River at Little Falls in Washington, D.C. The steel girder bridge carries close to 22,000 cars a day. It connects Washington with affluent sections of Arlington and Fairfax counties in Virginia. On the Washington side, the bridge connects with Canal Road. Left turns onto the Clara Barton Parkway from the Chain Bridge are prohibited, but the reverse is permitted. On the Virginia side, the bridge connects with State Route 123 (Chain Bridge Road), which provides access to the George Washington Memorial Parkway. The Chain Bridge has three lanes (of which the center is reversible) and can be safely accessed by pedestrians and cyclists. The pedestrian sidewalk provides access to the Chesapeake and Ohio Canal towpath via a ramp. The bridge also carries water mains which provides Arlington County with water from the Washington Aqueduct.

Merrywood is a historic home located in McLean, Virginia on the Palisades overlooking the Potomac River that has hosted several presidents and members of the British royal family. The Georgian Revival style brick dwelling was built in 1919 for Newbold Noyes.

The Dalecarlia Tunnel in Brookmont, Maryland, near Washington, D.C. is a former railroad tunnel that presently carries the Capital Crescent Trail underneath MacArthur Boulevard and the Washington Aqueduct. It was built in 1910 as part of the Georgetown Branch of the Baltimore and Ohio Railroad. It is a Roman arch tunnel, measuring 18 feet (5.5 m) wide by 340 feet (100 m) long. It features decorative brick facings on both ends and is lined with brick throughout its length. CSX Transportation, the successor to the B&O Railroad, ceased train operations through the tunnel in 1985 and officially abandoned the rail line in 1986.

Fort Ethan Allen was an earthwork fortification that the Union Army built in 1861 on the property of Gilbert Vanderwerken in Alexandria County (now Arlington County), Virginia, as part of the Civil War defenses of Washington (see Washington, D.C., in the American Civil War). The remains of the fort are now within Arlington County's Fort Ethan Allen Park.

Sibley Memorial Hospital is a non-profit hospital located in The Palisades neighborhood of Washington, D.C. It is fully accredited by the Joint Commission on Accreditation of Healthcare Organizations, and is licensed by the District of Columbia Department of Health and Human Services. The hospital specializes in surgery, orthopedics, and oncology services. It has been part of Johns Hopkins Medicine since 2010.

Dalecarlia Reservoir is the primary storage basin for drinking water in Washington, D.C., and Arlington County, Virginia. The reservoir is fed by an underground aqueduct in turn fed by low dams which divert portions of the Potomac River near Great Falls and Little Falls. The reservoir is located between Spring Valley and the Palisades, two neighborhoods in Northwest Washington, D.C., and Brookmont, a neighborhood in Montgomery County, Maryland.

Potomac Heights is a neighborhood in Northwest Washington, D.C., overlooking the Potomac River from MacArthur Boulevard westward. Potomac Heights is the part of the Palisades bounded to the north by Loughboro Road and to the south by Chain Bridge and Arizona Avenue NW. It is part of Advisory Neighborhood Commission 3D in Ward 3, the far northwest corner of the Northwest Quadrant just north of Georgetown.In June 1909, the Potomac Heights Land Co. (based in N.C.) acquired 75 acres (300,000 m2) previously known as the Athletic Park tract at the reported cost of $1000 an acre. The tract extends parallel with and between Conduit Road and the Potomac. It is divided by the Washington Railway and Electric Company and ran from Georgetown to Glen Echo for a 5 cent fare. There were 800 lots at $450–$500 per lot and no home was to be erected at less than $,2500. Sights in the area include Chesapeake & Ohio Canal National Historic Park, Andrew S. Edwards Island, and Chain Bridge.

The Intelligence Community Campus-Bethesda (ICC-B) is a campus in Brookmont, Maryland containing offices for several agencies of the United States Intelligence Community. The campus was created in 1945 and initially served as the headquarters of the National Geospatial-Intelligence Agency and its predecessor organizations. In 2012, it was transferred to the Office of the Director of National Intelligence and substantially renovated into an architecturally and functionally modern design.