Austen draws her portrait of Bath society from her own experience. Northanger Abbey, however, is probably as much a product of the Gothic novels that Austen read as it is a product of her own experience. A crumbling old building is often found in Gothic works, some of which feature an abbey, once used to house nuns or monks, then sold or abandoned and later purchased by some lord or baron who is generally a villain. The holy nature of the abbey becomes ironic in these Gothic novels, since terrible things go on there once the lord or baron takes possession.
For Catherine, Northanger Abbey symbolizes an imagined ideal. As soon as she enters the abbey, she begins to think of herself as the heroine of a Gothic novel. Unlike Bath, which is simply a pleasant tourist town, the Abbey is a place of mystery and perhaps even adventure, at least in Catherine's mind. When the Abbey turns out to be disappointingly normal, Catherine uses her memory of the abbeys from her novel-reading to make it more frightening.