Stunning pictures show inside a rainbow-colored “forgotten” sea cave that is thought to have special healing powers. The multicolored grotto was once one of Britain’s most mysterious sites and attracted huge numbers of visitors during the 17th and 18th centuries. The area is named after the cave’s healing waters where pilgrims, cripples, and sick people would make their way to the cave to drink from the “holy well.” But in recent decades, it has become largely secluded and unknown and most tourists now visiting Holywell, Cornwall, are unaware of its hidden wonders. The site, known as St Cuthbert’s Cave, creates mineral deposits leaving its stones red, green, blue and yellow. The spring water it creates was once described as the “elixir of life” in writings from the 19th century and were said to contain “life healing” minerals that trickled through the cave’s natural limestone. John Cardell Oliver’s “Guide to Newquay” …