St Paul's Cathedral is the seat of the Bishop of London. The present building, a 17th century construction designed by Sir Christopher Wren, used to be the tallest building in London till 1962. St Paul's dome is still among the highest in the world, surpassed only by St Peter's in Rome.
St Paul's is also famous for being the place where Charles, Prince of Wales and Lady Diana Spencer got married. For tourists interested to visit St Paul's Cathedral, it's good to know that there are no charges for people who want to attend the service. An admission fee is only applied for sightseeing.