Four Seasons Hotel London at Tower Bridge

What the classifiers highlight

Built in 1922 as headquarters for the Port of London Authority, this five-sided building survived Second World War damage and still holds its original grand staircase, now threaded by a glass elevator. Forbes notes the walnut-paneled UN Ballroom, site of the United Nations' first General Assembly in 1946, and an 18,083-square-foot spa below street level.