I just finished "The Willows", a short story by Alrgernon Blackwood in the Penguin Classics collection entitled "Ancient Sorceries and Other Weird Stories".
This was a masterpiece of supernatural fiction. Two friends set out to ride the Danube river in canoes, following it from it's source to it's mouth, camping on the way. All is well until they stumble upon an island that is a borderland close to the domain of unknown, otherworldly entities that do not take to kindly to their intrusion.
What I particularly like about this story is the way it moves from an idyllic, dream like world of beauty and happiness to sinister, malevolant world of fear and terror. The atmosphere and tension is masterfully built up ever so gradually. The many characters of the river on it's winding course were evokatively described, conveying the majesty and awe of it well.
I'm thinking that I really like this Algernon Blackwood.