Inside the Tower of London

Today, the Tower of London is kept pristinely clean, but it has a dirty past. For centuries, all its rubbish was chucked into the River Thames, but, as chief curator Tracy Borman discovers, yesterday's trash is today's treasure. She joins a team of archaeologists on the foreshore for a once-in-a-decade survey, and makes some remarkable finds, from thousand-year-old pottery to ancient armour