Big Ben

Big Ben is in London, the capital of the United Kingdom.

Many people think Big Ben is the tower. But Big Ben is really the name of the huge bell inside! The tall tower has a clock face on each side. When the bell rings, people all around can hear it.

Big Ben's tower stands at the north end of the Palace of Westminster, the building where the United Kingdom's Parliament meets, beside the River Thames.

Here is a surprise: Big Ben is really the nickname of the Great Bell that hangs near the top. The tower itself was called the Clock Tower, and in 2012 it was renamed the Elizabeth Tower. It is 96 meters tall, with 11 floors and a clock dial on each of its four sides. Parliament says that is as tall as 21 London buses stacked on top of each other.

The tower rises at the northern end of the Palace of Westminster, part of the World Heritage Site that UNESCO inscribed in 1987 with Westminster Abbey and St Margaret's Church; UNESCO calls the palace one of the most significant monuments of neo-Gothic architecture.

Parliament's own pages are careful with the names. Since it was built, the tower's official name was the Clock Tower; on June 25, 2012, the House of Commons Commission renamed it the Elizabeth Tower to mark Queen Elizabeth II's Diamond Jubilee. "Big Ben" belongs to the Great Bell, and Parliament says it is believed the bell was probably named in fun after Sir Benjamin Hall MP, the tall First Commissioner of Works who oversaw the later stages of the tower. The tower is 96 m high, with 11 floors, 334 steps to the belfry and another 65 to the Ayrton Light.

The tower has four big clock faces.

Each clock face is made of hundreds of glass pieces. Big Ben rings every hour. Four smaller bells play a tune every fifteen minutes.

Each of the four dials is 7 meters across and made of 324 pieces of opal glass in an iron frame. The minute hands are 4.2 meters long and made of copper.

Inside, a long pendulum swings, and each beat lasts 2 seconds. The clock is fine-tuned with old pennies: adding one penny makes it gain two-fifths of a second a day. In the belfry, Big Ben strikes the hours with the note E, and four smaller quarter bells play their tune every fifteen minutes.

Each dial, 7 m across, holds 324 pieces of pot opal glass in a cast iron frame. The copper-sheet minute hands are 4.2 m long and weigh 100 kg; the gunmetal hour hands are 2.7 m and 300 kg. Denison's double three-legged gravity escapement shields the mechanism from outside pressures such as wind on the hands. The 4.4 m pendulum, with a 203 kg bob of concentric steel and zinc tubes, beats every 2 seconds, and adding one pre-decimal penny makes the clock gain two-fifths of a second in 24 hours.

The bells are fixed and struck from outside by hammers. Big Ben, 13.7 tonnes with a 200 kg hammer, sounds E; the four quarter bells (1.1, 1.3, 1.7 and 4 tonnes) play the Cambridge Quarters, chosen by Denison from Great St Mary's in Cambridge. The old crack and the square cut-out are still visible. Above the dials, the Ayrton Light, installed in 1892, shines when either House of Parliament is sitting.

The tower was wrapped in scaffolding for five years while workers repaired it.

Now it looks bright and new again. The clock faces are blue and gold, just like long ago.

From 2017 to 2022, the tower was covered in scaffolding for what Parliament calls the most comprehensive repair in its history. More than 500 people from across the United Kingdom worked on it, using old crafts such as stone carving, gilding, glass work and clockmaking. For the first time, the Great Clock was taken completely apart and repaired.

Experts studied 160 years of paint and found the tower's first colors. For many years the dials had been painted black, but now they are Prussian blue and gold again, as Charles Barry designed them. Visitors aged 11 and over can book a tour and climb the 334 steps to stand next to Big Ben.

The conservation of 2017 to 2022, which Parliament calls the most comprehensive in the tower's history, repaired it from the gilt cross and orb at the tip to the base of its staircase. Surveys found pollution damage, asbestos and Second World War damage that the austere repairs of the 1950s had not fully fixed; the last major work had been in 1983 to 1985. The Great Clock was fully dismantled for the first time. The tour page puts the workforce at over 500 people.

Paint analysis with the University of Lincoln found six color schemes; the black dials probably dated from the 1930s, to mask pollution. The dials and hands are again Prussian blue and gold, the shields above each dial show St George's cross, and gilding matches 1859. A lift, fire systems and LED lighting, including in the Ayrton Light, were added. Tours, for visitors aged 11 and over, cost £55 for adults and £35 for children from August 1, 2026.