St Paul’s cathedral in the City of London was destroyed in the Great Fire of London (1666). A new baroque cathedral, designed by Sir Christopher Wren, was built over a roughly fifty year period, much quicker than the noticeably similar St Peters Basilica in the Vatican City (Rome). St Peter's took 120 years and seven architects to complete. St Paul’s was completed in 1711 although the fabric, as with all historic and contemporary buildings, has required constant maintenance since that time. In 1996 a major programme of renovation was began costing £40 million under the direction of heritage conservation specialists Martin Stancliffe Architects. About 150,000 blocks of (mainly) Portland stone were cleaned or replaced. Work finished in 2011 in time for the three hundredth anniversary of the original ‘topping out’ ceremony.