I'm not sure, but I think this story shows up frequently in anthologies. It did win a World Fantasy Award. I was aware when I started the story that it did deal with the theme of vampirism, and as the story opens I actually thought it might have been the journal of a "young" vampire girl. Even as the entries continue and that possibility seems less likely, I still couldn't quite be sure that there wouldn't be a final reveal that the author was a vampire all along. Again, Aickman does a great job with the atmosphere and keeping the reader just off balance enough.
The basic plot is that the narrative is a series of journal entries from a young Englishwoman as her family travels through Italy, where they tend to stay as guests of local landholders. There's an intriguing degree of allusions to other writers, particularly those of some Gothic importance. (As with Northanger Abbey, the narrator is fond of the Gothic works of Ann Radcliffe. She also learns that Shelley and Byron are staying nearby.) When it arrives, the vampire element is fairly conventional. (Who is that dark gentleman who the heroine is so drawn to?) The corruption of the narrator still makes more a compelling read and has a degree of ambiguity which reminded me of the end of "The Shadow Over Innsmouth."