London its political, economic and commercial centre. It is one of the lagest cities in the world and the largest city in Europe. There are some famous ancient building within the City. St Paul s Cathedral, the greatest of British churches. It was built in the 17 centery by Sir Christopher Wren. Westminster Abbey has more historic association then any other building in Britain. Nearly all english kings and queens have been crowened here. The Clock Tower of the Houses of Parliament is famous for its big hour bell, known as "Big Ben".
