Arlington National Cemetery is open to the public at 8 a.m. 365 days a year. From April 1 to Sept. 30 the cemetery closes at 7 p.m.; the other six months it closes at 5 p.m.

About Arlington National Cemetery:    
For the almost four million people who visit annually, Arlington National Cemetery represents many different things. For some, it is a chance to walk among headstones that chronicle American history; for many, it is an opportunity to remember and honor the nation's war heroes; and for others, it is a place to say a last farewell during funeral services for a family member or friend.

Facts about the Cemetery:

Arlington Mansion and 200 acres of ground immediately surrounding it were designated officially as a military cemetery June 15, 1864, by Secretary of War Edwin M. Stanton.

More than 260,000 people are buried at Arlington Cemetery.

Veterans from all the nation's wars are buried in the cemetery, from the American Revolution through the Persian Gulf War and Somalia. Pre-Civil War dead were reinterred after 1900.

The federal government dedicated a model community for freed slaves, Freedman's Village, near the current Memorial Amphitheater, Dec. 4, 1863. More than 1,100 freed slaves were given land by the government, where they farmed and lived during and after the Civil War. They were turned out in 1890 when the estate was repurchased by the government and dedicated as a military installation.

In Section 27, are buried more than 3,800 former slaves, called "Contrabands" during the Civil War. Their headstones are designated with the word "Civilian" or "Citizen."

Arlington National Cemetery and Soldiers Home National Cemetery are administered by the Department of the Army. All other National Cemeteries are administered by the Department of Veterans Affairs, or the National Park Service.

Arlington House (Custis-Lee Mansion) and the grounds in its immediate vicinity are administered by the National Park Service.

The flags in Arlington National Cemetery are flown at half-staff from a half hour before the first funeral until a half hour after the last funeral each day. Funerals are normally conducted five days a week, excluding weekends.

Funerals, including interments and inurnments, average 20 a day.

With more than 260,000 people buried, Arlington National Cemetery has the second-largest number of people buried of any national cemetery in the United States. Arlington National Cemetery conducts approximately 5,400 burials each year. The largest of the 130 national cemeteries is the Calverton National Cemetery, on Long Island, near Farmingdale, N.Y. That cemetery conducts more than 7,000 burials each year.

The Tomb of the Unknowns is one of the more-visited sites at Arlington National Cemetery The Tomb is made from Yule marble quarried in Colorado. It consists of seven pieces, with a total weight of 79 tons. The Tomb was completed and opened to the public April 9, 1932, at a cost of $48,000.

Three unknown servicemen are buried at the Tomb of the Unknowns:

A joint-service casket team holds a U.S. flag outstretched above the casket bearing the remains of the Vietnam Unknown, while President Ronald Reagan places a wreath at the casket's head during entombment ceremonies at Arlington National Cemetery.

Unknown Soldier of World War I, interred Nov. 11, 1921. President Harding presided. Unknown Soldier of World War II, interred May 30, 1958. President Eisenhower presided. Unknown Soldier of the Korean Conflict, interred May 30, 1958. President Eisenhower presided, Vice President Nixon acted as next of kin. An Unknown Soldier of the Vietnam Conflict, interred May 28, 1984. President Reagan presided. The remains of the Vietnam Unknown were disinterred May 14, 1998, and were identified as those of Air Force 1st Lt. Michael J. Blassie, whose family has reinterred him near their home in St. Louis, Mo. It has been determined that the crypt at the Tomb of the Unknowns that contained the remains of the Vietnam Unknown will remain empty.) The Tomb of the Unknowns is guarded by the U.S. Army 24 hours a day, 365 days a year. The 3rd U.S. Infantry (The Old Guard) began guarding the Tomb April 6, 1948.

On July 24, 1998, U.S. Capitol Police Officers John Michael Gibson, 42, and Jacob Joseph Chestnut, 58, were killed in the line of duty. They are buried in Arlington National Cemetery. Special Agent Gibson is buried in Section 28. Officer Chestnut, a retired Air Force master sergeant, is buried in Section 4.

In addition to in-ground burial, Arlington National Cemetery also has one of the larger columbariums for cremated remains in the country. Four courts are currently in use, each with 5,000 niches.

When construction is complete, there will be nine courts with a total of 50,000 niches; capacity for 100,000 remains. Any honorably discharged veteran is eligible for inurnment in the columbarium.

The Tomb of the Unknown:

The Tomb of the Unknowns at Arlington National Cemetery in Arlington, Va., is also known as the Tomb of the Unknown Soldier, and has never been officially named. The Tomb of the Unknowns stands atop a hill overlooking Washington, D.C. On March 4, 1921, Congress approved the burial of an unidentified American soldier from World War I in the plaza of the new Memorial Amphitheater.

The white marble sarcophagus has a flat-faced form and is relieved at the corners and along the sides by neo-classic pilasters, or columns, set into the surface. Sculpted into the east panel which faces Washington, D.C., are three Greek figures representing Peace, Victory, and Valor.

The Tomb sarcophagus was placed above the grave of the Unknown Soldier of World War I. West of the World War I Unknown are the crypts of unknowns from World War II, Korea and Vietnam. Those three graves are marked with white marble slabs flush with the plaza.

President Kennedy's grave site:

President Kennedy is only one of two presidents to be buried at Arlington National Cemetery.  Prior to his assassination in 1963, JFK commented on how peaceful he found the Arlington grounds.  After his untimely death, Kennedy was laid to rest in front of Arlington House overlooking Washington D.C.  His grave is marked by an eternal flame.

Additional Information:

John F. Kennedy's grave site:

http://www.arlingtoncemetery.org/visitor_information/JFK.html

http://ask.yahoo.com/ask/20010704.html

http://www.mdw.army.mil/fs-m01.htm

Arlington House:

http://www.nps.gov/arho/

http://www.nps.gov/gwmp/arl_hse.html

http://www.arlingtoncemetery.org/historical_information/arlington_house.html