 Companies that previously had their head offices in the City of Westminster include Imperial Chemical Industries (ICI), British Aircraft Corporation, British Midland (Portland House), British United Airways, British Mediterranean Airways, Cadbury, Diageo, BAA Limited, Lloyd International Airways, and P&O Princess Cruises.In addition, Iran Air previously had its Piccadilly main sales office in the city.The City of Westminster contains the some of the most famous sites in London, including Buckingham Palace, Westminster Abbey, the Palace of Westminster (Houses of Parliament) and Big Ben.