Nighttime Eiffel Tower is protected by copyright
Because the Eiffel Tower is a public building and its intellectual property right has expired (the architect died in 1919), one might assume that anyone may take photos of the Tower.
But apparently the nighttime light show on the Eiffel Tower, i.e. the Tower illuminated at night, is nevertheless under copyright protection.
The confusion is due to the fact that the 2001 EU directive includes a clause stating that photographing public buildings is free. Because the directive is optional, France, Belgium and Italy have not transposed it into law. Copyright legislation varies by country, but no reforms are foreseen in this area in the near future.