Three lighthouse keepers at Flannan Lighthouse on Eilean Mòr, Scotland, disappeared on December 15, 1900
On Boxing Day it was discovered that James Ducat, Thomas Marshall and Donald MacArthur had vanished
Search party climbed 160 steps up the cliffside and found a door ajar, an untouched meal and a toppled chair
Locals suggested one keeper murdered the other two and then thrown himself into the sea in a fit of remorse
Tales emerged that the men had been snatched by a sea serpent or taken away by a passing haunted ship
The mystery has never been solved and still remains one of the most puzzling in Scottish maritime history