What is that thing in the background on the right? Why, it's Sacré-Cœur, located at the summit of the Butte Montmartre in Paris, the highest point in the city! Construction of the basilica began in 1875, but wasn't completed until 1914.
Here's another in-between view, where the basilica appears to be not quite complete. As a side note, the obelisk in the center of the square was a gift from Egypt back in 1833. It was placed in the square in the exact location where the guillotine had stood, the same guillotine that killed Queen Marie Antoinette, Princess Élisabeth of France, Charlotte Corday, Madame du Barry, Georges Danton, Maximilien Robespierre, and thousands of others.