The Notre Dame Cathedral is the central symbol of Victor Hugo's novel. More than a house of worship or a grand building, it is an expression of the medieval culture of the characters and a symbol of how people are shaped by their surroundings. For example, Quasimodo finds comfort within the gothic confines of Notre Dame. Not only is it the only place where he is not mocked or persecuted, but even the stone figures throughout the space appear friendly to him:
His cathedral was enough for him. It was peopled with marble figures of kings, saints and bishops who at least did not laugh in his face and looked at him with only tranquillity and benevolence. The other statues, those of monsters and demons, had no hatred for him—he resembled them too closely for that. It was rather the rest of mankind that they jeered at. The saints were his friends and blessed him; the monsters were his friends and kept watch over him. He would sometimes spend whole hours crouched before one of the statues in solitary conversation with it.
Note that the grotesquery of the gargoyles in particular is a comfort to Quasimodo because they make him feel less horrible about his ghastly appearance. Both the saints and the monsters help give him a sense of identity and belonging, much as architecture does for most people within the culture that produced it.
Architecture in general plays a significant role in The Hunchback of Notre-Dame. Hugo makes architecture out to be a kind of text in a culture where most people did not have the ability to read. It is also an art form in which there is no one singular artist, as with a novel or painting. A building is born from the combined effort of many people, from the architect to the laborers. Hugo expands upon this idea, believing that architecture is "the offspring of a nation's effort"—that is, the expression of a society and a sort of historical text in its own way. In Hugo's novel, Notre Dame becomes the main symbol of this idea and a monument of medieval France.