The David Rumsey Map Collection website (USA) features a couple of Napoleonic maps available for consultation online.
One traces Napoleon Bonaparte's route from Elba to Paris between 26 February and 20 March, 1815, whilst the other depicts the extent of the French Empire in 1811.
The website features a powerful zoom function allowing the user to investigate the maps up close.
Napoleon Bonaparte's route from Elba to Paris (external link)
Empire of Napoleon Bonaparte, A.D. 1811 (external link)