Tomb of the Unknown Soldier

A Tomb of the Unknown Soldier or Tomb of the Unknown Warrior is a monument dedicated to the services of an unknown soldier and to the common memories of all soldiers killed in war. Such tombs are located in many nations and are usually high-profile national monuments. Throughout history, many soldiers have died in war with their remains being unidentified. Following World War I, a movement arose to commemorate these soldiers with a single tomb, containing the body of one such unidentified soldier.

Source: Wikipedia