The Tower of London is a historic castle located on the north bank of the River Thames and is one of the most popular tourist attraction in England. The construction of the castle was began in 1066 and the White Tower was built in 1078 by William the Conqueror. It was mostly used as a prison but it also served as an armoury, a treasury, a menagerie, the home of the Royal Mint, a public record office, and the home of the Crown Jewels of England.
Since the Elizabethan period the castle was one of the sights of London that attracted foreign visitors. The most popular attractions of the castle are the Royal Menagerie, displays of armour and Crown Jewels. The Tower of London steadily gained popularity through the 19th century and a purpose-built ticket office was erected in 1851 due to high number of tourists.