Jens Olsen's World Clock, located in Copenhagen City Hall, is a masterpiece of mechanical engineering and horology, completed in 1955 after 12 years of meticulous work. Designed by Danish clockmaker Jens Olsen, the clock features 12 movements and over 15,000 parts, displaying not just local time but also complex astronomical data, including planetary positions and solar eclipses, accurate for 2,500 years. With 10 different faces showing various times and celestial events, the clock remains a significant tourist attraction, celebrated for its precision and the ingenuity of Danish craftsmanship.