To celebrate Bastille Day ( 14 July ) or the 1944 Liberation ( 25August ) , blue , white , and red laser beams are bounced off the Eiffel Tower , Arc de Triomphe , and H ? ? tel de Ville .
Moments of silence and an eerie atmosphere accompany the darkening of all lights on the Eiffel Tower , Arc de Triomphe , and Hotel de Ville during the commemoration ceremonies of Bastille Day and 1944 Liberation Day .