If I were to find myself in the Flavian Amphitheater or the Pantheon after dark, it wouldn't really bother me, but I could not say the same of being stuck in a gothic cathedral. I would lose it jumping at every shadow. As I understood it, the Gothic art movement was sort of a more Northerly European alternative to the classical and neoclassical architecture/art popular in the Med. I mean yes there were the gothic novels like Dracula and Frankenstein, and that certainly played a role in influencing the association with nightmares. But was there any other underlying cause for that link? It just kind of blows my mind that such a widely popular artistic style that had existed separately for hundreds of years prior could be totally overshadowed and redefined by the popularity of a few novels?
This is something that stems in part from the 18th century novel. In Britain, at least, 'the Gothic' (both in art/architecture and in writing) was a fashionable novelty and a pastiche of medieval aesthetics; and as such it was constructed as a counterpoint to the prevailing 'rationalism' of the Enlightenment and neo-Classical styles.
So Gothic was associated with superstition and, to a certain extent, Catholicism - which in turn associated it with foreignness. This treatment of Gothic aesthetics made it a perfect backdrop for dramatic novels, such as Horace Walpole's 'The Castle of Otranto' (1764), Ann Radcliffe's 'The Mysteries of Udolpho' (1794) and Matthew Lewis' 'The Monk' (1796); all of which were set in Italy or Spain, both predominantly Catholic countries. Gothic writing was a form of exoticism, which drew upon ideas of the unfamiliar and the backward/barbaric to create a sense of horror and romantic terror.