London is a sight in itself- being burnt to ashes dozens of times, it is a fascinating mixture of architecture and cultures. So that it is impossible not to yield to temptation and have a London sightseeing tour. The estimated population of Greater London on 1 January 2005 was 7,421,228, and the population includes several million more in the wider metropolitan area, making London the largest city in the UK, and one of the largest metropolitan areas in Europe (along with Moscow and Paris).
Bus tours are the most popular tours of London, cause it is not only cheap but very convenient , and  gives a feeling of  slightly looking down at the fussy city`s life. Besides, all main London sights  the Tower of London, St. Paul's Cathedral, Whitehall, Trafalgar Square and Piccadilly, are available to be seen from the top of a double-decker.   The most prominent companies, providing such tours of London are Big Bus  Company, Classic Coach company,  London Ducktours, the Original Tour, etc
   As for the Original Tour, it  is the oldest company (founded in 1951 at the time of The Festival of Britain), now the largest and most popular sightseeing operator,  providing tours of London. They offer you  hop-on  hop-off service,  allowing   to board any of the buses along all of  London  tours at over 90 different stops. Entertaining 'live-guided' commentary are available  in a wide range of different languages.
Popular tours of London  to places of interest always  include Tower, Madam Tussaud''s, Piccadilly Circus, Covent Garden, Westminster Abbey,  Tower Bridge and a cruise on  the Thames. It has a great number of important buildings, including world-famous museums, theatres, concert halls, airports, railway stations, palaces, and offices. It is also the location of many foreign embassies, consulates and High Commissions, which are also have a story to tell.
 Bus tours of London though very  convenient do not give full idea of London, of course.  To discover all the secrets remained a mystery after a bus tour, take a walking one. These tours of London take place by any weather, and there is no need to book them beforehand, just come and join the company. And of course you can always explore London by yourself- it is even more exciting (but be careful about the winding mazes of  London`s streets).
  Whatever form of tours of London you choose, it is just impossible not to take notice of the British Airways London Eye - one of the most visually striking structures in the world. 
 The Eye takes you on a gradual, 30 minute, 360 degree rotation that will give you the kind of panoramic views usually only accessible by helicopter or aeroplane. For Londoners and visitors alike, it really is the best way have London sightseeing tours not spending the whole day on walk.

London's famous streets, churches, palaces and monuments spread out below in a panoramic scene grown up from Roman times - and, on a clear day - views that stretch 25 miles to Windsor Castle. And  this sweep is  really a breathtaking experience, as well as London itself.