The Plains of Jars. Thousands of giant stone jars are scattered around the Xieng Khouang plain in Laos. Excavation by Lao and Japanese archaeologists has supported the conclusion that these were funeral megaliths, with the discovery of human remains, burial goods and ceramics found in association with the stone jars. The Plain of Jars is dated to the Iron Age (500 BCE to 500 CE). Image: Anne Murray.