Turkey, Istanbul, Muslims praying during Friday prayers in a street near Taksim Square.

Turkey, Istanbul, Muslims praying during Friday prayers in a street near Taksim Square.

USA, Massachusetts, Boston, New England Holocaust Memorial.

USA, Massachusetts, Boston, New England Holocaust Memorial.

USA, Massachusetts, Boston, New England Holocaust Memorial.

USA, Massachusetts, Boston, New England Holocaust Memorial.

USA, Massachusetts, Boston, Old North Memorial Garden for fallen US soldiers in Iraq and Afghanistan, North End.

USA, Massachusetts, Boston, Old North Memorial Garden for fallen US soldiers in Iraq and Afghanistan, North End.

USA, New York City, Manhattan, Imagine mosaic memorial to John Lennon, Strawberry Fields, Central Park.

USA, New York City, Manhattan, Imagine mosaic memorial to John Lennon, Strawberry Fields, Central Park.

USA, New York City, Manhattan, New York Fire Department Memorial Wall, Engine 10, Ladder 10, World Trade Center.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.