While London’s top hotels tend to be concentrated in Mayfair and Knightsbridge, new luxury properties have begun moving into the financial district, breathing new life into a formerly quiet neighborhood. The impetus began with the Four Seasons Ten Trinity (fourseasons.com) opening at the Tower of London earlier this year, and in April, a hip new property again re-energized the area. With nine restaurants and bars, an impressive spa and fitness center and what is sure to be this summer’s hottest ...