The Sacred Heart Basilica of Montmartre, or Sacré-Coeur, is a major landmark in Paris. The site has a complex history from pagan times through the Middle Ages and French Revolution and is now a major cultural center in this popular neighborhood.
The Sacré-Coeur is constructed of stone from Château-Landon, which is known for it's high content of calcite. In damp weather calcite leaches out of the stone, keeping the appearance of the monument chalky white.