Mysterious symbols and letters, scratched into cave walls around 400-years ago by people warding off the evil of the Witch of Wookey Hole Caves, have been found.
The marks, which lay undiscovered for hundreds of years, were first thought to be graffiti.
But now specialists from Bristol University believe that an eerie draught of air spooked visitors to the caves prompting the ritual markings to be made.
They are now going to be displayed to the public for the first time at the attraction in Wookey, near Wells.
They were carved at a time when Matthew Hopkins, the Witchfinder General was responsible for hanging more than 300 women for witchcraft in the UK.
Wookey Hole Caves was found to have more ritual protection marks and symbols than any other cave, most of them in a vertical feature known as the Witches Chimney, close to the stalagmite that legend says is a witch turned to stone.
Daniel Medley, owner of Wookey Hole Caves, said: “We are always discovering new things in the caves and four new ritual protection markings were discovered when we were creating the Wild Wookey attraction for this year.
“Their discovery proved that the route our adventure cavers is the same one used in the Fifteenth Century, mentioned by William of Worcester in 1470.
“The fact that the Wild Wookey adventure cavers get a close-up look of the marks made us look at ways to enable visitors on our guided tours view them. We are now pointing them out and looking at ways to use the latest technology to protect them and illuminate a small area of the most accessible marks so that visitors to the caves can get a look at them.
“It is quite chilling to think that people hundreds of years ago were deep underground carrying flaming torches for light and scratching these symbols on the rocks because they believed it would protect them from the witch and her evil.
“Bristol University has carried out a full academic study and it is clear that the majority of these markings date from a period from 1550 to 1750. So there is evidence of 200 years of fear and superstition over the witch and her powers.”
The study carried out by Christopher Binding and Linda Wilson says: “The area in Wookey Hole where the majority of the ritual protection marks are located is a closed aven, which results in a convection draught caused by the body heat of those standing below it displacing the cooler surrounding air which then descends noticeably.”
The specialists believe that the effect would have been more pronounced years ago before a low rock lip was removed to make it easier for visitors to pass through, but it can still be felt today.
Many of the markings appear to be the letter W or the letter M but specialists believe they are really double V and are a reference to the Virgin Mary. Many others are Christian symbols also found in the timbers of houses as protection against evil.
Mr Medley added: “At first it was thought the markings were simply graffiti, people scratching their initials, but then you realise that it is the same letters over and over and the experts say these are symbols used to ward off evil and witches.
“Those were superstitious times and water for the whole area comes through these caves, so if there was a drought or illness among animals it was blamed on the caves and the witch. Of course in 1904 bones were found here along with other items, which proved conclusively that a woman lived here with a crystal ball, a goat and a bowl for mixing potions.
“The markings will now become part of our guided tours through the caves, which are enjoyed by visitors from all over the world.”