Lyndon Baines Johnson Memorial Grove on the Potomac

The Navy – Merchant Marine Memorial, located in Lady Bird Johnson Park on Columbia Island in Washington, D.C., is a monument honoring sailors of the United States Navy, Coast Guard, the United States Merchant Marine, the NOAA Commissioned Officer Corps and others who died at sea during World War I and other times. It was designed in 1922 by Harvey Wiley Corbett and sculpted by Ernesto Begni del Piatta, who died before it could be completed. It was cast in a foundry in Cleveland. Ground was broken on the memorial in 1930, with the foundation completed the following year and it was installed on October 18, 1934, but work on the base and landscaping was postponed due to lack of funding. A dedication ceremony was held on May 30, 1935. Funding was finally approved by Congress to finish the memorial in 1939 and work began anew the following September, to be completed by the end of the year.Nicknamed "Waves and Gulls," the memorial depicts seven seagulls above the crest of a wave. It is cast from aluminum and the base is made of green granite from New Hampshire (the base was originally concrete but replaced by the Works Progress Administration). It stands 35 feet (10.6 m) tall and 30 feet (9.1 m) wide. It is the first aluminum memorial in Washington, DC. The memorial reads: To the strong souls and ready valor of those men of the United States who in the Navy, the Merchant Marine and other paths of Activity upon the waters of the world have given life or still offer it in the performance of heroic deeds this monument is dedicated by a grateful people.

Boundary Channel is a channel off the Potomac River in Washington, D.C. The channel begins at the northwestern tip of Columbia Island extends southward between Columbia Island and the Virginia shoreline. It curves around the southern tip of Columbia Island before heading northeast to exit into the Potomac River. At the southwestern tip of Columbia Island, the Boundary Channel widens into the manmade Pentagon Lagoon.

Lady Bird Johnson Park, formerly known as Columbia Island until 1968, is an island located in the Potomac River in Washington, D.C., in the United States. It formed naturally as an extension of Analostan Island in the latter part of the 1800s, and over time erosion and flooding severed it from Analostan, now known as Theodore Roosevelt Island. The U.S. federal government deposited material dredged from the Potomac River on the island between 1911 and 1922, and again from 1925 to 1927. The island was also reshaped by the government at this time "to serve as the western terminus of Arlington Memorial Bridge and a symbolic entrance into the nation’s capital." Located within the park are the Lyndon Baines Johnson Memorial Grove, Navy – Merchant Marine Memorial, and the Columbia Island Marina. The island, park, memorials, and marina are part of the George Washington Memorial Parkway and administered by the National Park Service.

John Ericsson Memorial, located near the National Mall at Ohio Drive and Independence Avenue, SW, in Washington, D.C., is dedicated to the man who revolutionized naval history with his invention of the screw propeller. The Swedish engineer John Ericsson was also the designer of USS Monitor, the ship that ensured Union naval supremacy during the American Civil War.The memorial was authorized by Congress August 31, 1916, and dedicated May 29, 1926 by President Calvin Coolidge and Crown Prince Gustaf Adolf of Sweden. Congress appropriated $35,000 for the creation of the memorial, and Americans chiefly of Scandinavian descent raised an additional $25,000. Constructed on a site near the Lincoln Memorial between September 1926 and April 1927, the pink Milford granite memorial is 20 feet (6.1 m) high with a 9-foot (2.7 m) diameter base. Sculpted by James Earle Fraser, it features a seated figure of Ericsson 6 feet 5 inches (1.96 m) high, and three standing figures representing adventure, labor, and vision. The national memorial is managed by National Mall and Memorial Parks.

Pentagon Army Heliport (ICAO: KJPN, FAA LID: JPN) is a military heliport serving the Pentagon. It consists of a single pentagon-shaped helipad and is located on the northern side of the Pentagon building. It is used for ferrying VIPs such as military leaders and foreign guests to and from the Pentagon by helicopter.

The First Air Mail Marker is a plaque in West Potomac Park, Washington, D.C. It is located on east shore of the Potomac River beside Ohio Drive. The marker commemorates the first regularly scheduled United States airmail service flight. On May 15, 1918, Lt. George Boyle departed Washington in a Curtiss JN-4H biplane in front of a crowd that included President Woodrow Wilson. Bound for Philadelphia, Boyle became disoriented and landed in a Maryland field. The marker was erected on the flight's fortieth anniversary, May 15, 1958.

The Pentagon is the headquarters building of the United States Department of Defense. It was constructed on an accelerated schedule during World War II. As a symbol of the U.S. military, the phrase The Pentagon is often used as a metonym for the Department of Defense and its leadership. Located in Arlington County, Virginia, across the Potomac River from Washington, D.C., the building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on 11 September 1941, and the building was dedicated on 15 January 1943. General Brehon Somervell provided the major impetus to gain Congressional approval for the project; Colonel Leslie Groves was responsible for overseeing the project for the U.S. Army Corps of Engineers, which supervised it. The Pentagon is the world's largest office building, with about 6.5×10^6 sq ft (150 acres; 60 ha) of floor space, of which 3.7×10^6 sq ft (85 acres; 34 ha) are used as offices. Some 23,000 military and civilian employees, and another 3,000 non-defense support personnel, work in the Pentagon. It has five sides, five floors above ground, two basement levels, and five ring corridors per floor with a total of 17.5 mi (28.2 km) of corridors. The central five-acre (2.0 ha) pentagonal plaza is nicknamed "ground zero" on the presumption that it would be a prime target in a nuclear war.In 2001, the Pentagon was damaged during the September 11 attacks. Five al-Qaeda hijackers flew American Airlines Flight 77 into the western side of the building, killing themselves and 184 others: 59 on the airplane and 125 in the Pentagon. It was the first significant foreign attack on Washington's governmental facilities since the city was burned by the British during the War of 1812. Following the attacks, the western side of the building was repaired, with a small indoor memorial and chapel added at the point of impact. An outdoor memorial dedicated to the Pentagon victims of 9/11 opened in 2008.

The National Military Command Center (NMCC) is a Pentagon command and communications center for the National Command Authority (i.e., the President of the United States and the United States Secretary of Defense). Maintained by the Department of the Air Force as the "DoD Executive Agent" for NMCC logistical, budgetary, facility and systems support; the NMCC operators are in the Joint Staff's J-3 (Operations) Directorate. "The NMCC is responsible for generating Emergency Action Messages (EAMs) to missile launch control centers, nuclear submarines, recon aircraft and battlefield commanders".

The National Military Command System (NMCS) was the federal government of the United States' Cold War command and control system that consisted of the National Military Command Center (NMCC) at The Pentagon, the Alternate National Military Command Center (NMCC) at Pennsylvania Raven Rock Mountain, 3 National Emergency Airborne Command Post (NEACP) aircraft on 24-hour ground alert, 2 National Emergency Command Post Afloat (NECPA) ships, "and interconnecting communications".

West Potomac Park is a U.S. national park in Washington, D.C., adjacent to the National Mall. It includes the parkland that extends south of the Lincoln Memorial Reflecting Pool, from the Lincoln Memorial to the grounds of the Washington Monument. The park is the site of many national landmarks, including the Korean War Veterans Memorial, Jefferson Memorial, Franklin Delano Roosevelt Memorial, George Mason Memorial, and the Martin Luther King Jr. Memorial. The park includes the surrounding land on the shore of the Tidal Basin, an artificial inlet of the Potomac River which was created in the 19th century, an inlet that links the Potomac with the northern end of the Washington Channel. West Potomac Park is administered by National Mall and Memorial Parks, an administrative unit of the National Park Service's National Capital Parks.

The Defense POW/MIA Accounting Agency (DPAA) is an agency within the U.S. Department of Defense whose mission is to recover American military personnel listed as prisoners of war (POW) or missing in action (MIA) from designated past conflicts, from countries around the world.

The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national security and the United States Armed Forces. The DOD is the largest employer in the world, with over 1.4 million active-duty service members (soldiers, marines, sailors, airmen, and guardians) as of 2021. More employees include over 826,000 National Guard and reservists from the armed forces, and over 732,000 civilians bringing the total to over 2.8 million employees. Headquartered at the Pentagon in Arlington, Virginia, just outside Washington, D.C., the DoD's stated mission is to provide "the military forces needed to deter war and ensure our nation's security".The Department of Defense is headed by the secretary of defense, a cabinet-level head who reports directly to the president of the United States. Beneath the Department of Defense are three subordinate military departments: the Department of the Army, the Department of the Navy, and the Department of the Air Force. In addition, four national intelligence services are subordinate to the Department of Defense: the Defense Intelligence Agency (DIA), the National Security Agency (NSA), the National Geospatial-Intelligence Agency (NGA), and the National Reconnaissance Office (NRO). Other Defense agencies include the Defense Advanced Research Projects Agency (DARPA), the Defense Logistics Agency (DLA), the Missile Defense Agency (MDA), the Defense Health Agency (DHA), Defense Threat Reduction Agency (DTRA), the Defense Counterintelligence and Security Agency (DCSA), the Space Development Agency (SDA) and the Pentagon Force Protection Agency (PFPA), all of which are subordinate to the secretary of defense. Additionally, the Defense Contract Management Agency (DCMA) is responsible for administering contracts for the DoD. Military operations are managed by eleven regional or functional Unified combatant commands. The Department of Defense also operates several joint services schools, including the Eisenhower School (ES) and the National War College (NWC).