Wikipedia
The Church of Saint-Jean-de-Montmartre is located at 19 Rue des Abbesses in the 18th arrondissement of Paris.
Situated at the foot of Montmartre, it is notable as the first example of reinforced cement in church construction. Built from 1894 through 1904, it was designed by architect Anatole de Baudot, a student of Viollet-le-Duc and Henri Labrouste. The brick and ceramic tile-faced structure exhibits features of Art Nouveau design while exploiting the superior structural qualities of reinforced concrete with lightness and transparency. The Art Nouveau stained glass was executed by Jac Galland according to the design of Pascal Blanchard. Interior sculpture was by Pierre Roche.
The reinforced concrete structure followed a system developed by the engineer Paul Cottancin. Construction was attended by skepticism over the properties of the new material, which violated rules laid down for unreinforced masonry construction. A lawsuit delayed construction, resulting in a demolition order that was not resolved until 1902, when construction was resumed.
There is a guided tour of the church on every fourth Sunday of the month at 4:00 PM.