The historic Tower of London can be found on the north bank of the River Thames in London. When it was built the tower's primary function was as a fortress, a royal palace, and a prison. It has also served as a place of execution and torture, an armoury, a treasury, a zoo, the Royal Mint, a public records office, an observatory, and since 1303, the home of the Crown Jewels. Two of the most famous sights at the tower are the resident ravens and its Beefeaters. According to legend, the entire kingdom will fall if the ravens ever leave the tower. Meanwhile, the Beefeaters serve as defenders of the Crown Jewels, prison guards, and, since the time of Queen Victoria, tour guides to visitors.