This novel is widely recognised as being one of the most famous Gothic novels in the English language, as it contains all of the critical ingredients necessary for a Gothic novel. Gothic novels normally contained naive and innocent heroines who were entrapped by evil and dastardly males who had sexual designs on them. A young, brave and upright hero battles to save her and the setting is normally based in a ruined castle, an abandoned abbey or a place that is far away from civilisation and the rest of humanity.
The setting is a key aspect of Gothic fiction, as it highlights the way that Gothic literature exaggerates human emotions. Being so far away from the restraining influence of civilisation, the responses of the characters--the hysteria of the damsel in distress, for example-- is that much more acute. It highlights the way in which Gothic novels are psychological novels, and the responses of the characters are extreme emotional and passionate responses that move them beyond the realms of normal experience and into the hinterland of the unconscious and psychological realm of emotions and passions. You might find this a useful way of examining the range of extreme emotions as expressed in this novel, perhaps especially the hysteria of Isabella.