More on London

The Tower of London was once used mainly as a prison. William Wallace from Scotland was kept there and later executed on the grounds at Tower Hill. Wallace was not the only one to be executed within the walls of the Tower of London.  Henry VI, Edward V and Richard Plantaganet were some others from history. It wasn't until the nineteenth century that architects started studying the design of the Tower and came to consider it a historical site/building (http://www.essortment.com/tower-london-history-21046.html).
In 1876, the City of London Corporation in charge of the east end of the Thames River decided that the growing city needed a bridge to be built in that part as soon as possible. Years before, the London Bridge was the only way across the river. As the city grew they built more bridges to the west of the London Bridge, but not to the east because that part was used as a port. With it taking hours to get from the north side to the south, and vice versa, they finally started working on different ideas/designs for a bridge that would still allow ship activity. In October 1884, after 50 different designs had been submitted throughout the years, the Tower Bridge design was accepted. "It took 8 years, 5 major contractors and the relentless labor of 432 construction workers to build Tower Bridge" (http://www.towerbridge.org.uk/TBE/EN/BridgeHistory/). It is called the "Tower Bridge" because of the two towers, one either side.