Archaeological site Durrington Walls in Wiltshire

You're standing at Durrington Walls, about two miles north-east of Stonehenge. Have a look around. That low ridge in the grass, circling a wide basin, is what's left of a huge henge. That's a ring made of an earth bank with a ditch on the inside. On the eastern side you can still make out the bank and ditch best, even though centuries of ploughing have worn them down. Originally the ditch was about five and a half metres deep, and in places the bank was thirty metres wide.