The world-famous clock tower at the Palace of Westminster in London is officially called the Elizabeth Tower. It was renamed in 2012 to honor the Diamond Jubilee of Queen Elizabeth II; prior to that, it was simply known as the "Clock Tower." The name most people use, "Big Ben," actually refers only to the Great Bell inside the tower, which weighs 13.7 tons and strikes the hourly chimes. Designed by Augustus Pugin and completed in 1859, the 96-meter tower is an icon of Gothic Revival architecture. In 2026, following a massive multi-year restoration, the tower is fully operational, with its four clock faces illuminated by energy-efficient LED bulbs. A unique tradition remains: the clock's accuracy is still adjusted by adding or removing old British penny coins from the pendulum; adding a single penny speeds up the clock by 0.4 seconds per day, ensuring it remains one of the most accurate mechanical public clocks in the world.