This is the Sacré-Cœur in Montmartre (photo from when I had my little Amélie pilgrimage in January ^_^). One of the most beautiful si(gh)tes in the city; it sits on top the hill of Montmartre, and you can see most of Paris from the plaza in front. Something about the light the day this photo was taken made it seem even more ethereal, I suppose... that's precisely how it looked, no editing to the shot or whatnot. Still one of my favorite photos that I've taken.
For more on Sacré-Cœur, go here.