1. History: The clock tower that houses Big Ben was completed in 1859 and officially named the Elizabeth Tower in 2012 to mark Queen Elizabeth II's Diamond Jubilee. The nickname "Big Ben" originally referred to the Great Bell inside the tower but is now commonly used to refer to the entire structure. 2. Great Bell: The Great Bell, commonly known as Big Ben, weighs over 13.5 tons and strikes the hour with a distinctive deep tone. It is one of the most famous bells in the world and has become a symbol of London. 3. Clock Mechanism: The clock mechanism of Big Ben is one of the largest and most accurate in the world. It was designed by Edmund Beckett Denison and Edward Dent and features a double three-legged gravity escapement, which ensures its accuracy. 4. Dials: The clock faces on the four sides of the tower are 23 feet (7 meters) in diameter and are made up of 312 pieces of opal glass. The hour hand is 9 feet (2.7 meters) long, and the minute hand is 14 feet (4.3 meters) long. 5. Chimes: The chimes of Big Ben are well-known around the world and consist of four notes played at every quarter-hour. The chimes are broadcast by the BBC and are a familiar sound to many people in the UK.

6. Restoration: In recent years, Big Ben has undergone significant restoration work to ensure its continued operation and accuracy. The tower has been scaffolded for restoration work, and the clock faces have been cleaned and repaired. 7. Symbolism: Big Ben and the Elizabeth Tower are iconic symbols of London and are featured in countless photographs, postcards, and films. The tower is also a UNESCO World Heritage Site and a popular tourist attraction. 8. Accuracy: Despite its age, Big Ben's clock mechanism remains remarkably accurate, with adjustments made periodically to ensure precise timekeeping. The clock is regularly checked against an atomic clock to maintain its accuracy.