Big Ben.

While most use the name to describe the entire 316-foot Gothic Revival tower, Big Ben technically refers to the 13.7-ton Great Bell hanging within the belfry. Designed by Augustus Pugin and completed in 1859, the Elizabeth Tower serves as the architectural exclamation point for the Houses of Parliament. Its four clock faces are composed of 312 pieces of opal glass, housing a Victorian mechanism famous for its near-perfect precision. A recent multi-year restoration refreshed the landmark's intricate masonry and returned the clock hands to their original Prussian blue. Inside, a 334-step spiral staircase leads past a former prison cell to the mechanism room and the belfry. It remains the city's most enduring symbol of resilience, still chiming across the Thames over 160 years after its first ring.