Hartog Plate or Dirk Hartog's Plate.

The Dirk Hartog dish, or plate, displayed in the Rijksmuseum, Amsterdam. According to the museum: "Arrived here on 25 October 1616", is the message on this flattened pewter dish. En route to Java, VOC captain Dirck Hartogh accidentally happened upon Australia’s west coast. Before sailing on he had the date, the ship’s name and destination, and the names of the most important crew members scratched into this dish. He nailed it to a pole, where it hung exposed to the elements until another Dutch captain found and took it close to 80 years later. (VOC are the initials of Vereenigde Oost-Indische Compagnie, the Dutch East India Company). The plate is the earliest artifact known of Europeans landing on Australian shores.