Fodor's Expert Review St. James's Square
One of London's oldest squares, St. James's was first laid out in the 1660s. It soon became the capital's most fashionable address; by 1720, it was home to 14 dukes and earls. These days you're more likely to find it populated with office workers eating their lunches under the shade of its leafy old trees on a warm summer's day, but it still has some prestigious residents. Most famous among them is the London Library at No. 14, one of the several 18th-century residences spared by World War II bombs. Founded by Thomas Carlyle, it contains a million or so volumes, making it the world's largest independent lending library, and is also considered the best private humanities library in the land. Nonmembers can take a free evening tour of the library on alternate Mondays at 6 pm, although reservations must be made in advance.