Avebury is famous as the site of some of the oldest prehistoric structures in England. The village is on the River Kennet, southeast of Chippenham, England. It stands inside a great circular earthwork that formed part of an Iron Age fort. Avebury has a circle of stones about 1,000 feet (305 meters) across. Most of the stones are about 8 feet (2.5 meters) tall, but some are more than 19 feet (6 meters) tall. Nearby stands Silbury Hill, the largest tumulus (artificially created mound) in Europe.