When the Atlantic high tides flood the caves, the water gushes up through these massive holes in the ground and hillside. This is apparently where the mythical figure Hercules went to rest after he finished his twelve labours.

It is unsure how the caves were exactly formed as they are partially natural and partially manmade. It has been rumored that an ancient civilization for some reason used to carve millstone out of the solid rock that made giant caves over the years which have all baffled experts as to how they could have done it with such simple and crude tools that they had.

The colours within the caves at low tide are breathtaking, but it is advised that if your not a strong swimmer do not to venture into the ocean as the currents offshore can be very strong and quite dangerous. It has also been said that the caves of St Michaels were once joined and that it would have been possible for the Barbary Apes to cross over.