ARLINGTON NATIONAL CEMETERY
Arlington National Cemetery is perhaps the most famous cemetery in the world. It is approximately 612 acres, nestled in the hills overlooking the capital and the Lincoln Memorial, and is the final resting place for more than 285,000 American military men and women who fought and died in battles from the Revolutionary War to present day. Among the people buried here are:  President John F. Kennedy, his widow Jacqueline Kennedy Onassis, and his brother Sen. Robert Kennedy, Supreme Court Justice Thurgood Marshall, prizefighter Joe Louis and astronaut "Gus" Grissom. Alsolocated on the grounds is a memorial to the crew of the space shuttle Challenger, the Tomb of theUnknown Soldier (guarded 24 hours), and Arlington House, Robert E. Lee’s former home.
Metro: Arlington Cemetery. Hours: Open daily, 8am to 7pm. Admission: Free.

FRANKLIN D. ROOSEVELT MEMORIAL
A 7.5-acre site, the memorial, dedicated in 1997, depicts the 12 pivotal years of Franklin Delano Roosevelt's presidency through a series of four outdoor gallery rooms. The rooms feature ten bronze sculptures depicting President Roosevelt, Eleanor Roosevelt and events from the Great Depression and World War II. The park-like setting includes waterfalls and quiet pools amidst a meandering wall of reddish Dakota granite, where Roosevelt's inspiring words are carved. It is the first memorial in Washington, DC purposely designed to be totally wheelchair accessible.
Metro: Smithsonian. Hours: Open daily, 8am to midnight. Admission: Free.

JEFFERSON MEMORIAL
The Jefferson Memorial was authorized in 1934 and dedicated in 1943, on Jefferson's 200th birthday. The memorial is modeled after Rome's Parthenon, with a dome that is 129 feet tall. The memorial features a bronze statue of Thomas Jefferson facing the White House, standing 19 feet tall, and on a 6 foot tall granite pedestal. The interior of the monument has carved passages from the Declaration of Independence as well as other famous Jefferson writings.
Metro: Smithsonian. Hours: Open daily, 8am to midnight. Admission: Free.

KOREAN WAR VETERANS MEMORIAL
This privately funded memorial, founded in 1995, honors those who served in Korea, a 3-year conflict (1950-53) that produced almost as many casualties as Vietnam. It consists of a circular "Pool of Remembrance" in a grove of trees and a triangular "Field of Service," highlighted by lifelike statues of 19 infantrymen, who appear to be trudging across fields. In addition, a 164-foot-long black-granite wall depicts the array of combat and support troops that served in Korea (nurses, chaplains, airmen, gunners, mechanics, cooks, and others); a raised granite curb lists the 22 nations that contributed to the U.N.'s effort there; and a commemorative area honors KIAs, MIAs, and POWs.
Metro: Foggy Bottom-GWU. Hours: Open daily, 8am to midnight. Admission: Free.

LINCOLN MEMORIAL
The Lincoln Memorial has been a fixture on the National Mall since 1922. This memorial to Abraham Lincoln has been the site of many famous gatherings and speeches, with the most famous one being Martin Luther King's "I Have a Dream" speech in 1963. The Lincoln Memorial was built in the style of a Greek temple, with 36 columns, one for each state at the time of Lincoln’s death. Inside the memorial, a 19-foot tall statue of Lincoln sits looking east toward the Washington Monument and the Capitol. Passages from the Gettysburg Address and Lincoln's second Inaugural Address are carved into the walls. The Lincoln Memorial, overlooking the Reflecting Pool, is an impressive site to visit after the sun has set and the lighting illuminates the building.
Metro: Foggy Bottom-GWU. Hours: Open daily, 8am to midnight. Admission: Free.

MARINE CORPS MEMORIAL IWO JIMA STATUE
One of the largest bronze statues ever cast, this memorial commemorates all the marines who have died in battle since 1775. The memorial depicts the moment of triumph as five Marines and a Navy soldier raised the American flag at Mt. Suribachi on the island of Iwo Jima in 1945.  The statue was created by Felix deWeldon and is based on a famous photograph taken by Joe Rosenthal. 
Metro: Rosslyn. Hours: Open daily, 24 hours. Admission: Free.

NATIONAL WORLD WAR II MEMORIAL
Dedicated in 2004 and located between the Washington Monument and Lincoln Memorial, this memorial honors the 16 million who served during WWII and those who supported the war effort from home. The memorial features two 43-foot arches, a 17-foot pillar for each state and territory from that period and a field of 4,000 gold stars honoring the more than 400,000 who died. A series of bronze sculpture panels depict Americans at war, at home and overseas.
Metro: Smithsonian. Hours: Open daily, 24 hours. Admission: Free.

VIETNAM VETERANS MEMORIAL
The Vietnam Veterans Memorial is possibly the most poignant sight in Washington: two long, black-granite walls in the shape of a V, each inscribed with the names of the men and women who gave their lives, or remain missing, in the longest war in American history.The two walls are angled at 125° to point to the Washington Monument and the Lincoln Memorial. The wall's mirror-like surface reflects surrounding trees, lawns, and monuments. The names are inscribed in chronological order, documenting an epoch in American history as a series of individual sacrifices from the date of the first casualty in 1959. The National Park Service continues to add names over the years, of those Vietnam veterans who die eventually of injuries sustained during the war. At present, the walls list close to 60,000 people. Also part of the memorial are the Three Servicemen Statue and the Vietnam Women's Memorial, which were added in years subsequent to the memorials dedication in 1982.
Metro: Foggy Bottom-GWU. Hours: Open daily, 24 hours. Admission: Free.

WASHINGTON MONUMENT
The most prominent landmark in Washington, DC,  the Washington Monument, stands as the centerpiece of the National Mall. At 555 feet tall, it towers over the skyline as the tallest structure (and the world's tallest freestanding work of masonry). Authorized by Congress in 1833 and designed by architect Robert Mills, construction began in 1848. In 1854, with the Civil War looming, construction halted for almost 25 years. It took until 1878 for building to resume (you can still see a change in the color of the stone about halfway up). The exterior of the obelisk was finally completed in 1884 and President Chester A. Arthur dedicated the landmark in 1885.  The interior opened to the public in 1888. Today, an elevator takes visitors on the 70 second trip up to the 500 foot landing for magnificent views of the city. The Washington Monument lies at the very center of Washington, DC; landmarks and its 360-degree views are spectacular. Like being at the center of a compass, the monument provides a marvelous orientation to the city.
Metro: Smithsonian. Hours: Open daily, 9am to 5pm. Admission: Free.