Much of Paris was built from its own underland, hewn block by block from the bedrock and hauled up for dressing and placing. Underground stone-quarrying began in earnest towards the end of the twelfth century, and Parisian limestone grew in demand not just locally but across France. Lutetian limestone built parts of Notre-Dame and the Louvre; shipped on Seine barges into the river network, it became a major regional export.
