Three graves, four wars, one eternal watch: the history behind the Tomb of the

The Tomb of the Unknown Soldier at Arlington National Cemetery in Arlington County, Virginia, USA, is the burial site of a World War I soldier whose remains were unidentifiable. Now, it houses the graves of three unknown soldiers: one each from WWI, WWII, and the Korean War. Each man's service number was minted into the edge of a silver coin, a token of their sacrifice and service in the hands of their comrades-in-arms. But the real guardian is the Tomb itself, with its sentries standing watch, day and night, a promise to never forget their sacrifice.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons