Perk up with a caffeine boost and breakfast at Monmouth Coffee, then walk east to cross Tower Bridge and admire the 11th-Century Tower of London.

BBC: A perfect day in London

Cross the bridge, pausing to admire the view, and climb Tower Hill to the Tower Of London.

CNN: The story

If not for the level, you'd have to walk uphill to cross your bedroom, pencils would roll right off your desk and the Empire State Building might look like the Leaning Tower of Pisa.

FORBES: No. 18 The Level