THE TOWER OF LONDON.
Although Shakespeare asserts that Julius Caesar began the building of the Tower of London, the oldest part of it now extant is the White Tower, which easily dominates the rest of the structure. This White Tower, or Keep, was erected by William the Conqueror in 1078, is 92 ft. high, and has walls 13-14 ft. thick. The Tower generally, which lies outside the old city, is the most famous fortress in the world, but from time to time it has undergone great transformations. Once it was a royal palace; then, the chief State prison; and now it serves as a Government arsenal and barracks, as well as a public show place. The view from outside the moat here presented enables the extent of the buildings, covering 13 acres, to be well appreciated.
source: The Queen's London : a Pictorial and Descriptive Record of the Streets, Buildings, Parks and Scenery of the Great Metropolis, 1896