S4·E9 Magic Circles

Film 1: As the world waits for Halley's Comet, a recently discovered diary written by a 17th-century merchant from Rye in Sussex reveals the feelings of a man caught up in a scientific revolution, when the new discipline of astronomy shouldered aside the age-old belief in astrology. Author Aubrey Burl, authority on stone circles, outlines new theories which suggest that the ancient peoples of Britain used the world's most famous circle as a lunar as well as a solar observatory.

Film 2: A look back at events earlier this year when Stonehenge and the hill fort at Maiden Castle were at the centre of English Heritage's controversial plans to preserve our past - a controversy that still rages over who digs what and where, that has split the usually placid world of archaeology.