Trafalgar Square
 
The square was originally called Charing. Later it became known as Charing Cross, after a memorial cross on the square. The nearby underground station (the 'tube') is still named Charing Cross.
In 1812 the architect John Nash redevelop the area. After much delay work finally started in 1830 but Nash died before that his plans were realized so works were halted.  
                                                 
  Nelson's Column
 
The name of the square commemorates the victory of Admiral Nelson over the French fleet at the Battle of Trafalgar, a naval battle that took place on the 21st of October 1805 near Cape Trafalgar, just off the Spanish coast.  
there were no plans for a statue in honor of the admiral, who lost his life during the battle. Finally, in 1838, it was decided that Trafalgar Square was the ideal place for a monument to Britain's most famous admiral and a competition was organized to select a design for the 'Nelson Testimonial'.