A long time ago, a man with a lot of free time on his hands decided to go through the libraries of New York City and London and compile all the unusual phenomena he found records of (fish falling from the sky, red rain, etc). That man was Charles Fort, and his publishing of the same materials over the course of 30 years of research made him a minor celebrity. Unexplained phenomena are still sometimes referred to as “Fortean,” and there is a rather credulous pop-cultural British magazine called The Fortean Times dedicated to the same purpose today.
I have a folder in my “Lovecraft” directory called “Real Things That Aren’t Lovecraft But Could Be.” In that folder, among others, are a couple websites relating to the Flannan Isles Disappearance of 115 years ago today.
The Flannan Isles lay northwest of Scotland, on the North Atlantic. Sometime after 9am on December 15th, 1900, the three men responsible for manning the lighthouse on Eilean Mor disappeared, leaving very little indication of what had happened behind. While the most likely explanation is that they were swept away by a freak wave or waves, the eerie details of the scene left behind are ripe for any kind of fantastical storytelling (aliens, monsters, ghosts, etc). I refer you to two pages about the events here:
The normal-seeming scene at the lighthouse suggests the far more famous case of the Mary Celeste:
Surprising twists and turns in that one, beyond the simple discovery. Might make a good movie.