St Paul's Cathedral, London, is a Church of England cathedral, the seat of the Bishop of London and mother church of the Diocese of London. Architect - Sir Christopher Wren, built between 1675 - 1720 in the English Baroque style.
There are doors and 760 windows in Buckingham Palace. All windows are cleaned every six weeks to keep them clean. Buckingham Palace has its own chapel, post office, swimming pool, staff cafeteria, doctor's surgery and cinema.