The timeline for perhaps the most famous of all Gothic Cathedrals, Notre Dame, was built along the Seine River in Paris between 1163 and 1250. It took the notion of the grand cathedral and expanded into the point of nigh make-believe. With its fabulous swinging flying buttresses, its mind-boggling expanses of stained glass windows became a sort of beat-this-if-you-can prototype to haunt France throughout the next century.
To support its one hundred foot towering but almost tissuey thin walls, double-span flying buttresses were conceived to shoulder all the extra weight. Though the concept of the flying buttress surely existed prior to Notre Dame, it could be argued that here it was taken to monumental level and etched what would become the most prominent feature of the Gothic Cathedral into the evolving gray matter of the Gothic mind.
What startles one as he looks at Notre Dame is its outward strength. It is built like a box, and does not appear to have an Achilles heel. Built in the form of a cross, aka cruciform, its grand squatness rises up in enormous vaults, expatriate in nature, and covers double bays.
Its interior features a lovely arcade of columnar piers and has four separate levels of elevation. All of it is lit by the gigantic rose windows as well as smaller occuli openings in the tribune roof spaces and diminutive clerestory windows as well. The vertical and horizontal strength of the space creates an aura of calm and divinity unconcerned with the imperfections of the perhaps unkind and unfair world beyond it cut stone walls.