Big Ben's clock bell traditionally marks midnight during London's televised New Year's Eve celebration.
Big Ben is the nickname commonly used for the Great Bell of the Palace of Westminster, although the name is often used informally for the entire clock tower. The tower was renamed the Elizabeth Tower in 2012, while the bell retained the name Big Ben.
At midnight on December 31, the clock's chimes are broadcast as London welcomes the new year. Crowds gather around the River Thames and nearby central London areas, where fireworks are also staged. Television coverage uses views of the tower and the river to make the chimes a recognizable part of the national countdown.
The clock tower is not itself the location of London's main fireworks launch area. The fireworks are arranged along the Thames, and visibility from public locations depends on tickets, crowd controls, and weather. Big Ben therefore supplies the iconic time signal, while the riverside display supplies the major visual spectacle.