What is Big Ben actually the name of?

Big Ben is the bell - thirteen and a half tonnes of it, hanging in the tower at the north end of the Palace of Westminster. The tower was called simply the Clock Tower until 2012, when it was renamed the Elizabeth Tower for the Diamond Jubilee. Whom the bell was named after is not settled: either Sir Benjamin Hall, the commissioner who oversaw the installation, or Ben Caunt, a heavyweight boxer of the day.

It is famous partly for being flawed. The first bell cracked during testing and had to be recast. The replacement cracked too, within months of being hung in 1859, and rather than recast it again they turned the bell so the hammer struck elsewhere, fitted a lighter hammer, and left the crack. The particular note London knows is the sound of a broken bell.

The clock itself is remarkable engineering, accurate to about a second and adjusted by putting old pennies on the pendulum - each penny gains the clock roughly two fifths of a second a day. It kept time through the Blitz, and the chimes were broadcast to occupied Europe as a signal that London was still there.