The Evzones, in Athens, Greece, are an elite military unit, guarding the Tomb of the Unknown Soldier, 24 hours per day.They also perform at various ceremonial occasions. According to the different seasons, the uniform color also changes. On Sundays, they wear a light weight White uniform, Navy, as in this photo, and a light weight gray uniform.Their practice is rigorious. Precision from head to toe is required with no smiles allowed.