In its day, the construction of Stonehenge was an impressive engineering feat, requiring commitment, time and vast amounts of manual labor. In its first phase, Stonehenge was a large earthwork; a bank and ditch arrangement called a henge, constructed approximately 5,000 years ago. It is believed that the ditch was dug with tools made from the antlers of red deer and, possibly, wood. The underlying chalk was loosened with picks and shoveled with the shoulderblades of cattle. It was then loaded into baskets and carried away. Modern experiments have shown that these tools were more than equal to the great task of earth digging and moving.