Unlike royal tombs in many other parts of the world, the Joseon Royal Tombs have not been robbed by grave robbers. Whenever archaeologists examined a grave, they found the dead man or woman still had a crown, gold, jewels, or other valuable grave goods. As far as scholars can tell, the only people to ever dig up Joseon Royal Tombs were modern archaeologists, starting in 1930 during the Japanese occupation of Korea. That team was careful to treat the tomb with respect so that the people of Korea would not become angry. Scholars know which king or queen was buried in some tombs and do not know which king or queen was buried in other tombs. Archaeologists only dig up tombs whose owner is not known.