It's Memorial Day weekend in the United States, a time when we honor war dead. (We honor living veterans on Veterans' Day in November.)
This is the USS Maine Mast Memorial in Arlington National Cemetery in Arlington County, Virginia. The USS Maine exploded in Havana Harbor, Cuba, on February 15, 1898. Most sources say the ship carried 354 crew, but the numbers range from 327 to 375. The number of dead is also unclear. Most sources say 252, 260, or 266, but it could be as high as 274.
Most of the dead were buried at Colon Cemetery in Havana. Some were inexplicably taken to Key West, Florida, and interred in a civilian cemetery there. (The number buried at Key West ranges from 19 to 27, although most say 24.)
In December 1899, the Cuban dead were moved to a large field behind a quarry at Arlington National Cemetery, at which time they were given a massive state funeral.
From 1910 to 1912, the U.S. Navy engaged in a salvage operation to raise the wreck of the Maine. Additional dead were discovered at this time, and interred at Arlington. Congress funded a memorial to the Maine dead during this time. Dedication of the Maine Mast Memorial by President Woodrow Wilson occurred on May 30, 1915, as part of larger Memorial Day ceremonies at Arlington National Cemetery.