PHOTOS: Here, the heroes rest in peace

Prime Minister Narendra Modi visited the Arlington National Cemetery in the United States on Tuesday and paid tributes to fallen soldiers.

He is the second Indian prime minister to visit Arlington after Jawaharlal Nehru, who went there in 1949.

Here are a few interesting facts about the 152-year-old cemetery in whose 624 acres those who died in the nation's conflicts are buried.

IMAGE: A little boy touches a photograph of his US Marine father, while visiting his grave at Arlington National Cemetery in Washington, US. Photograph: Lucas Jackson/Reuters

Arlington National Cemetery contains the remains of more than 4,00,000 people from the Unites States and 11 other countries, buried there since the 1860s. More than 4 million people visit the cemetery annually.

The cemetery was born out of the American Civil War and has the second-largest number of people buried of any national cemetery in the US.

IMAGE: A soldier kisses the grave of his friend in Section 60, the burial ground for military personnel killed since 2001, at Arlington National Cemetery. Photograph: Allison Shelley/Getty Images

US presidents are eligible to be buried at Arlington whether or not they served on active duty since they oversaw the armed forces as commanders-in-chief. Two former Presidents -- John F Kennedy and William Howard Taft -- are buried here.

IMAGE: Visitors embrace as they sit next to a grave at Arlington National Cemetery. Photograph: Lucas Jackson/Reuters ph: Allison Shelley/Getty Images.

Five state funerals -- including those of Kennedy and Taft -- have been held at Arlington. The other ones being the funerals of JFK’s two brothers, Senator Robert F Kennedy and Senator Edward 'Ted' Kennedy, and General of the Armies John J Pershing.

IMAGE: A four-year-old girl stands with her brother and father Greg at the grave of a college friend of her father killed in Iraq in 2004 at Arlington National Cemetery. Photograph: Allison Shelley/Getty Images

'The Tomb of the Unknown Soldier' or simply ‘The Tomb of the Unknowns’ is a memorial to the dead of World War I, World War II, the Korean War and the Vietnam War. The tomb has the following words inscribed: ‘Here rests in honored glory An American Soldier Known but to God.’ The 'Unknown Soldier of the Vietnam War' was interred on May 28, 1984 by President Ronald Regan.

IMAGE: A bugler plays ‘Taps’ during the funeral of a military personnel at Arlington National Cemetery. Photograph: Alex Wong/Getty Images Images

Three of the five soldiers who raised the US flag on Iwo Jima during World War II are buried at Arlington.

IMAGE: A US army soldier visits the grave of his fellow marine at Arlington National Cemetery. Photograph: Lucas Jackson/Reuters

Arlington has a memorial dedicated to the astronauts -- including Indian-American astronaut Kalpana Chawla -- who died on board Space Shuttle Columbia when in disintegrated while re-entering into the earth’s orbit on February 1, 2003.

IMAGE: US President Barack Obama participates in wreath-laying ceremony at the ‘Tomb of the Unknown Soldier’ in observance of Memorial Day at Arlington National Cemetery. Photograph: Yuri Gripas/Reuters raph: Lucas Jackson/Reuters

Burial in Arlington is generally limited to active, retired and former members of the armed forces, Medal of Honor recipients, high-ranking federal government officials and their dependents. However, there’s a long list of who can be buried here, which also includes, among others, an elective office of the US government, office of the Chief Justice of the US or of an associate justice of the Supreme Court of the US.