The column was built between 1840 and 1843 to commemorate Admiral Horatio Nelson's death at the Battle of Trafalgar in 1805. The 18ft statue of Nelson stands on top of a 183 ft granite column. The statue faces south, towards the Palace of Westminster and along Pall Mall, where his ships are represented on the top of each flagpole. The top of the Corinthian column is decorated with bronze acanthus leaves cast from British cannons. The square pedestal is decorated with four bronze panels, cast from captured French guns, depicting Nelson's four great victories.
Pretty cool. If you want to learn more about the restoration go here.
If you want to see the panoramic view from the top of the column go here.