If the find was dated to 1920, it might have been war booty. At that time, it was shortly after the First World War, and owning such a large amount of valuables could have been extremely dangerous. It is likely that the person who buried it never had the chance to return.
RE: Hikers Stumble Upon Hidden Treasure Chest Containing 3.7 kg of Gold Coins and Century-Old Jewels in Czech Mountains