system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the tomb of the unknown soldier guarded so thoroughly?
gpt
It began in the 1920's to keep people from having picnics on top of the tomb.  We keep the tradition going to honor the unnamed dead.  The guards are called Sentinels and are all volunteers from the 3rd Infantry.  They are awarded the Tomb Guard Identification Badge after some time of service and some tests.  It is one of the highest non combat honors the Army awards.  It is a special wreath pin that is worn on the right pocket.