Beneath the Sgurr are some sea caves that were cut when the sea was higher. The big one is Cathedral cave. Nearby a smaller cave, Uamh Fhraing (also known as the Massacre Cave) saw the death of almost the entire population of the MacDonalds who inhabited Eigg. In 1577, 395 Macdonalds hid in the cave from a group of raiding McLeods from Skye.They were found and the McLeods lit a fire at the only entrance. They all died and the corpses were left in the cave to rot. As recently as 1979 a human skull was found in the cave.
In those dark days in Eigg's past, it was not banks of fog on the water but smoke.