When William the Conqueror built a mighty stone tower at the centre of his London fortress in the 1070s, defeated Londoners must have looked on in awe. Now nearly 1000 years later, the Tower still has the capacity to fascinate and horrify. As protector of the Crown Jewels, home of the Yeomen Warders and its legendary guardians, the pampered ravens, the Tower now attracts over three million visitors a year. Here, the Ceremony of the Keys and other traditions live on, as do the ghost stories and terrible tales of torture and execution. But the Tower also has a richer and more complex history, having been home to a wide array of institutions including the Royal Mint, the Royal Armouries and even a zoo.