Big Ben

Big Ben is technically the 13.7-tonne bell hanging inside the neo-Gothic Elizabeth Tower at the north end of the Palace of Westminster, though the name is used the world over for the clock and tower alike. Completed in 1859 to Augustus Pugin's design, its four dials and hourly chimes have become the visual and audible shorthand for London itself, tolling through royal deaths, New Year's Eve broadcasts and wartime newsreels.

With a 4.6 rating across nearly 100,000 reviews, it draws almost everyone who passes through Westminster, even though most visits amount to a look and a photo rather than an entry — the tower itself is only open to UK residents on a separate pre-booked tour. It suits a quick stop worked into a wider walk along the Thames rather than a dedicated outing.