london100 St Paul's Cathedral St Paul's is Christopher Wren's greatest architectural achievement and England's national church. There's been a church on this spot since 604 AD. It was the symbol of London's rise from the Great Fire of 1666 and of it's survival of the Blitz in 1941. The current cathedral -- the fourth to occupy this site -- was built between 1675 and 1710 after its predecessor was destroyed in the Great Fire of London.