London underground or the 'Tube', as the Londoners call it, is a rapid transit system in the big city and is used by thousands of people everyday, locals as well as tourists. It's the fastest & most convenient way to get from one place to another in no time bypassing the busy & crowded streets of London. The underground usually gets very busy at the rush hour; therefore, it's better to ride it at the 'off peak' hours which can be a bit cheaper as well.

 


 

It is the oldest underground railway in the world, the first section of which opened in 1863 & trains were steam-hauled, requiring effective ventilation to the surface through shafts at various points on the route which allowed the engines to expel steam and bring fresh air into the tunnels. In 1890 it became the first metro system to operate electric trains.
The earlier lines were built by various private companies but since 2003 it has been wholly owned by Transport of London, a corporation responsible for most aspects of the transport system in Greater London, which is run by a board and a commissioner appointed by the Mayor of London.The Underground serves 270 stations and has 402 kilometers of track, making it the second largest metro system in the world after Shanghai Metro and the 3rd busiest metro system in Europe after Moscow & Paris.

 
         


The Central Line, which was opened in 1900, is the longest and second busiest after the Northern Line. The second longest is the Piccadilly Line which was opened in 1906. There are ongoing plans for extensions to the Lines as well as upgrading and refurbishment of many stations in preparation to the London Olympics in 2012.
 

             

So if you're in London, do what the locals do, use the Tube. It's fast, it's efficient, and it's convenient. Just try to avoid the rush hour.