No conspiracies or UFOs... this is a rather unusual hole coin. Perhaps inspired by the Chinese cash coin, this is cast in Indonesia during Indragiri sultanate around 1610 - 1620. Indragiri shows up as Sumatra today - not sure if that is the origins of where this coin is cast. Inscription is an old Javanese text of 40 (repeated 6 times). Seems to be rather uncommon. . https://www.omnicoin.com/coins/1063313.jpg Very limited information can be found here https://www.zeno.ru/showgallery.php?cat=11308 I don't know of any other examples with such pentagon hole...