Notre-Dame de Paris also known as Notre-Dame Cathedral or simply Notre-Dame, is a medieval Catholic cathedral on the Île de la Cité in the fourth arrondissement of Paris, France. The cathedral is widely considered to be one of the finest examples of French Gothic architecture, and it is among the largest and most well-known church buildings in the world. The naturalism of its sculptures and stained glass are in contrast with earlier Romanesque architecture.
Notre-Dame de Paris was among the first buildings in the world to use the flying buttress. The building was not originally designed to include the flying buttresses around the choir and nave but after the construction began, the thinner walls grew ever higher and stress fractures began to occur as the walls pushed outward. In response, the cathedral’s architects built supports around the outside walls, and later additions continued the pattern. The total surface area is 5,500 m² (interior surface 4,800 m²).