Several historical bridges named London Bridge have spanned the River Thames between the City of London and Southwark, in central London. The current crossing, which opened to traffic in 1974, is a box girder bridge built from concrete and steel. This replaced a 19th-century stone-arched bridge, which in turn superseded a 600-year-old medieval structure. This was preceded by a succession of timber bridges, the first built by the Roman founders of London.
The current bridge stands at the western end of the Pool of London but is positioned 30 metres (98 ft) upstream from previous alignments. The traditional ends of the medieval bridge were marked by St Magnus-the-Martyr on the northern bank and Southwark Cathedral on the southern shore. Until Putney Bridge opened in 1729, London Bridge was the only road-crossing of the Thames downstream of Kingston-upon-Thames. Its importance has been the subject of popular culture throughout the ages such as in the nursery rhyme "London Bridge Is Falling Down" and its inclusion within art and literature.
The modern bridge is owned and maintained by Bridge House Estates, an independent charity overseen by the City of London Corporation. It carries the A3 road, which is maintained by the Greater London Authority. The crossing also delineates an area along the southern bank of the River Thames, between London Bridge and Tower Bridge, that has been designated as a business improvement district.
The current London Bridge was designed by architect Lord Holford and engineers Mott, Hay and Anderson. It was constructed by contractors John Mowlem and Co from 1967 to 1972, and opened by Queen Elizabeth II on 17 March 1973. It comprises three spans of prestressed-concrete box girders, a total of 928 feet (283 m) long. The cost of £4 million (£51 million in 2015), was met entirely by the Bridge House Estates charity. The current bridge was built in the same location as Rennie's bridge, with the previous bridge remaining in use while the first two girders were constructed upstream and downstream. Traffic was then transferred onto the two new girders, and the previous bridge demolished to allow the final two central girders to be added.
In 1984, the British warship HMS Jupiter collided with London Bridge, causing significant damage to both ship and bridge.
On Remembrance Day 2004, several bridges in London were furnished with red lighting as part of a night-time flight along the river by wartime aircraft. London Bridge was the one bridge not subsequently stripped of the illuminations, which are regularly switched on at night.
The current London Bridge is often shown in films, news and documentaries showing the throng of commuters journeying to work into the City from London Bridge Station (south to north). A recent example of this is actor Hugh Grant crossing the bridge north to south during the morning rush hour, in the 2002 film About a Boy.
On Saturday, 11 July 2009, as part of the annual Lord Mayor's charity Appeal and to mark the 800th anniversary of Old London Bridge's completion in the reign of King John, the Lord Mayor and Freemen of the City drove a flock of sheep across the bridge, supposedly by ancient right.
In vaults below the southern abutment of the bridge is 'The London Bridge Experience.'