St Stephen's Tower is more famously known as Big Ben.
However Big Ben is actually the name of the 13 ton bell housed in the huge tower.

St Stephen's Tower is situated at the northern end of Westminster Bridge
and London's Westminster Palace, also known as the Houses of Parliament.

Construction of the tower was started in 1843, and is 316 feet tall, 200ft of which is the belfry.
It was completed 13 years later in 1856, and was designed by Sir Charles Barry & Augustus Pugin.

It was Pugin who designed the 23ft diameter clock face.
The tower has four of these clock faces.
The hour hands are 9ft long, and the minute hands 14ft.
The Roman numerals measure 2ft.
These faces are cleaned by window cleaners, who have to abseil from a balcony in the Belfry to reach them.
There is an inscription beneath each dial which reads...
'DOMINE SALVAM FAC REGINAM NOSTRAM VICTORIAM PRIMAM'
meaning
'Lord save our Queen Victoria I'

Besides the huge hour bell (Big Ben),
there are 4 quarter bells weighing
1 ton, 1.25 tons, 1.6 tons & 3.5 tons.
They were designed by Edmund Beckett Denison.

There are 340 steps in the tower,
290 of them have to be climbed to reach the Clockroom, the remaining steps leading to the belfry.

St Stephen's Tower is recognised round the World as one of London's best known landmarks.

Information written by Angel
resourced from personal local knowledge,
and facts verified in various websites & books
(see links in above info).