The harbour is said to have witnessed a miracle during the Dark Age. The Vikings made an assault on the Isle of May, which was then the home of St Adrian. He was slaughtered, and his body was lain to rest on the island. One morning some fishermen in Anstruther Harbour saw a strange sight in the early morning mist, floating towards them, carried on the tide was a stone coffin. They pulled it ashore and inside found the preserved remains of St Adrian. He is said to have been reburied in the local churchyard.