On the Surface- its a buzzing, modern metropolis. But Underneath lie secret,hidden worlds,all but forgotten by the millions of people above.This is the bit the general public dont usually see. Digging down deep, we will unearth some of the most extraordinary stories of London's subterranean history...(Air raid Siren and falling bombs).. a world of ancient caves and preserved roman ruins and we are now coming into the amphitheater itself. For those in the know, there really is a darker side to this city. This is the secret world underneath London. This program like you thank you. Modern London is built on layers of history. All you have to do is dig down deep to discover. Secret hiding places used in World War 11...masterpiece of Victorian engineering...remnants of the Industrial revolution...millions of medieval bones ...even forgotten rivers.................................