text: The 122-year-old Victorian structure spanning the River Thames last underwent refurbishment in 1970.
  The City of London Corporation, said work will take place on the timber decking, lifting mechanism and water proofing its brick arches.
  The bridge will close for road traffic until 30 December but pedestrians can walk across on all but three weekends.
  A free cross river ferry service will run when it is closed to pedestrians.
  Tower Bridge will also continue to be open for river traffic and the viewing gallery along the walkways of the bridge will also remain open.
  More than 21,000 vehicles and 40,000 people use the bridge everyday, owner the City of London Corporation said.
  "This heavy use has had an effect on timber decking of the bridge, which was last refurbished in 1970.
  "To ensure that the Bridge continues to serve as a vital river crossing we need to undertake the essential maintenance works," the corporation said.
  Nearby Tooley Street is also closed eastbound until 2018 to allow Network Rail's rebuilding of London Bridge railway station.
  Northbound traffic will be diverted via London Bridge and southbound via Southwark Bridge, and the works will be "disruptive", Transport for London (TfL) has said.
  TfL said the diversions take people into the congestion charging zones but motorists will not be charged as long as they keep to the routes marked specifically as diversions.
  Source: Tower Bridge Exhibition
target: London's landmark Tower Bridge has closed to traffic on Saturday until the end of December for maintenance work.