How many wars/conflicts are represented by the Tomb of The Unknown Soldier?
Throughout history, many soldiers have died in wars without their remains being identified. In modern times, nations have developed the practice of having a symbolic Tomb of the Unknown Soldier that represents the war grave of those unidentified soldiers. They usually contain the remains of a dead soldier who is unidentified (or “known but to God” as the stone is sometimes inscribed) and thought to be impossible ever to identify, so that he might serve as a symbol for all of the unknown dead wherever they fell. The anonymity of the entombed soldier is key to the symbolism of the monument: since his or her identity is unknown, it could theoretically be the tomb of anyone who fell in service of the nation in question, and therefore serves as a monument to all of their sacrifices. Much work goes into trying to find a certain soldier, and to verify that it is indeed one of the relevant nation’s soldiers. See Wikipedia for national examples.