The first London Bridge was built by the Romans slightly downstream (c. 50AD). It has been re-built several times. The version built between 1176 and 1209 originally had houses, shops and a chapel on it. Replaced in 1831 by John Rennie's bridge which is now in Arizona, USA
London Bridge was the only bridge in London until the mid 18th century
The present bridge dates from 1973 and cost £4 million. It carries 1,600 vehicles per hour between 7am and 10am.