Marine archaeologists have discovered a wreck dating from the 13th century off the coast of Japan . The vessel is believed to have been part of Kublai Khan 's massive invasion fleet . More than 200 artifacts , including wooden vessels , cannonballs and anchors were found near the wreck .
Marine archaeologists have found a shipwreck dating from the 13th century off the coast of Japan . The vessel is thought to have been part of Kublai Khan 's massive invasion fleet . More than 4,000 artifacts , including pottery shards , cannonballs and anchors were found near the wreck .