The Tower of London is a London landmark and a major visitor attraction. The White Tower, the square building with turrets on each corner that gave it its name, is actually in the middle of a complex of several buildings along the River Thames in London, which have served as fortresses, armories, treasuries, zoos/menageries, mints, palaces, places of execution, public records offices, observatories, shelters, and prisons (particularly for upper class prisoners). This last use has led to the phrase "sent to the Tower" meaning to be "imprisoned".
One well known example was Elizabeth I who was imprisoned for a time in the Tower during her sister Mary's reign. According to Shakespeare, in his play Richard III, the Tower of London was built by Julius Caesar. This supposed Roman origin is, however, just a myth. Its true foundation was in 1078 when William the Conqueror ordered the White Tower to be built.
Lower-class criminals were usually executed by hanging at one of the public execution sites outside the Tower. Several high-profile convicts, such as Thomas More, were publicly executed on Tower Hill. Nobles (especially ladies) were sometimes beheaded privately on Tower Green, inside the complex, and then buried in the "Chapel Royal of St. Peter ad Vincula". The Queen Anne Boleyn, beheaded in 1536 for treason against King Henry VIII, is said to be occasionally seen walking around the tower carrying her head under her arm.
The Crown Jewels - have been kept in the Jewel House at the Tower since 1303 after they were stolen from Westminster Abbey, where armed guards now defend them.
To get there from the Americana; take the Jubilee Line from Baker Street to Westminster and change to the District & Circle Line. Go to the eastbound platform and take the first train to Tower Hill.
The Tower is next to the station.