The Elizabeth Tower is the clock tower of the Palace of Westminster in London, England. It contains the Great Clock, a striking clock with five bells. The tower is nicknamed Big Ben, a name which was originally applied only to the largest bell of the clock.

Inside the Elizabeth Tower (commonly known by its largest bell, Big Ben) is a complex 11-story structure rising 96 meters above London. The interior is largely occupied by a spiral stone staircase with 334 steps leading to the belfry. On the way up, you encounter the Mechanism Room, which houses the massive Victorian-era clock movement weighing five tonnes. This legendary machine uses a 4.4-meter pendulum and pre-decimal pennies to maintain its famous accuracy. Above the clock faces is the Belfry, where the 13.7-tonne "Great Bell" (Big Ben) hangs alongside four smaller quarter bells. At the very top, another 65 steps lead to the Ayrton Light, a lantern that remains lit when Parliament is in session. Following extensive 2020s renovations, the interior now also features a modern elevator for accessibility, though most tours still involve the traditional climb. The walls are a mix of brick and stone, specifically limestone from France and Yorkshire, creating a historic, industrial atmosphere that feels worlds away from the polished streets of Westminster below.