The Tower Bridge is a world famous suspension bridge over the River Thames. It is located close to the Tower of London.

After eight years of construction the Tower Bridge was completed in 1894 and instantly hailed as a London icon and one of the great engineering marvels of its age. The bridge is 60 meters (197 ft) long and its two towers rise to a height of 43 meters. The two towers are tied together at the upper level by means of two horizontal walkways. The high-level walkways between the two towers gained an unpleasant reputation as a haunt for prostitutes and pickpockets and were closed in 1910 and not reopened until 1982. The walkways boast stunning views of the River Thames and many famous London sights, serving as viewing galleries for over 380,000 tourists who visit each year.

When it was built, Tower Bridge was the larges and most sophisticated bascule bridge ever built. It was a hydraulically operated bridge, using steam to power the enormous pumping engines. The energy created was then stored in six massive accumulators so that, as soon as power was required to lift the bridge, it was readily available. The accumulators fed the driving engines, which drove the bascules up and down. Despite the complexity of the system, the bascules only took about a minute to raise to their maximum 86 degrees.

Nowadays, the bascules are still operated by hydraulic power, but since 1976 they have been driven by oil and electricity rather than steam. The original pumping engines, accumulators and boilers are on show as part of the Tower Bridge Exhibition, and you can also see the current machinery and control cabins when you come on a "Behind the Scenes Tour". Behind the Scenes tours must be pre-booked.