Killone Lake is home to a haunting legend that has been etched into local folklore for centuries. They say a mermaid who frequented the lake's waters had a taste for wine, often sneaking into the crypt beneath the nearby church or the cellar of Newhall to steal a bottle. But her thieving spree came to an abrupt end when she was caught and stabbed, or perhaps shot, depending on who you ask. The mermaid managed to drag herself back to the lake before succumbing to her injuries, and it's said that every forty years, the waters of Killone Lake turn red with her blood.

Historical records are scarce, but the story of the bloodied mermaid has been passed down through generations of locals. The tale has become synonymous with the lake, and many believe that the mermaid's spirit still roams the waters. While there's no concrete evidence to support the existence of mermaids, the legend has become an integral part of Irish folklore. The phenomenon of the lake's waters turning red has been observed by multiple witnesses, although the exact date of the occurrence is unknown. It's said to happen every forty years, leaving onlookers with a chilling reminder of the mermaid's tragic fate.