The Tower Bridge, named after its two impressive towers, is one of London's best known landmarks and one of the most recognized bridges in the world.  Designed by Sir Horace Jones and engineered by Sir Wolfe Barry, the construction of the Tower Bridge began in 1886 and ended 8 years later. After Jones death in 1887, Barry was able to invoke greater artistic freedom than he would have under the original designers' supervision. The towers, covered in ornate Victorian masonry, stand 206 ft., 63 m. tall and are constructed of a steel frame. The structure has a main span, the Catwalk, of 200 ft., 61 m., with a bascule roadway and two steel walkways which are 140 ft., 43 m. high.  Popularity has increased sense the bridge was first opened, and it is now one of London's best loved landmarks.

To the center, two mobile parts, heavy over 1000 tons, raise themselves completely to allow the transit of the greatest ships. Anciently the raising was maneuvered with a hydraulic system that exploited the strength of the vapor to operate the enormous systems of pumping. Produced energy in 6 voluminous accumulators was stored so that it was suffered available when it was necessary to lift the bridge. The accumulators fed the mechanisms of lifting and lowering of the mobile parts, that, although the complexity of such system, the mobile parts employed around only one minute to reach the maximum opening of 86 degrees. Today the mobile parts of the bridge is still lifted through the hydraulic system that anyway since1975 it is not operated with the vapor anymore but using electricity power.

It used to be raised about 50 times a day, but nowadays it is only raised 4 to 5 times a week.