The Plain of Jars is an ancient archaeological site located in the Xieng Khouang province of Laos. It is home to thousands of megalithic stone jars, believed to date back to the Iron Age. The jars range in size from one meter to three meters in height
From Wikipedia
The Plain of Jars is a megalithic archaeological landscape in Laos. It consists of thousands of stone jars scattered around the upland valleys and the lower foothills of the central plain of the Xiangkhoang Plateau. The jars are arranged in clusters ranging in number from one to several hundred.