The Basilica of the Sacred Heart of Paris, commonly known as Sacré-Cœur Basilica, is a Roman Catholic church and minor basilica, dedicated to the Sacred Heart of Jesus, in Paris, France. A popular landmark, the basilica is located at the summit of the butte Montmartre, the highest point in the city. Wikipedia
This place is a must see while visiting Paris. It has great views of the city. Don’t miss the opportunity to check out the area under the church grounds. Very cool!