A team of archaeologists have been working on the uninhabited island off the east coast of Sweden, known as Bla Jungfrun. The name translates in English as The Blue Virgin, given to the island by sailors to appease the evil spirits it was believe lived there. The island has been a National Park since 1926 and is currently home to a large colony of black guillemots. Visitors are allowed but cannot stay over night or disturb anything.
     It is not known how long the island has been associated with evil spirits and witchcraft but evidence has been uncovered by the team which points to at least the Stone Age and maybe further back in time. The island shows signs of intense human activity during the Mesolithic Age and the team has been concentrating their research around two caves which have provided substantial evidence of ritualistic behaviour.
     The first cave has a strange hollow which has been hammered out of one of its vertical walls, accompanied by a fireplace at its base. Whilst it is believed that the hollow is man-made, its purpose is purely conjectural, but the layout of the rest of the cave may provide a clue.
     Papmehl-Dufay, team member and an archaeologist from Kalmar County Museum (Sweden) is quoted as saying "The entrance to the cave is very narrow and you have to squeeze your way in. However once you are inside only half of the cave is covered and you can actually stand above the cave and look down into it, almost like a theatre or stage below." The hollow and fireplace stand at the centre of this stage like area. Other caves and shelters have provided further evidence such as a hammerstone, grinding area, stone tools and the fossilised bones of 9,000 year old seals. Are these seals the remains of a ritual feast or simply the evening meals of fishermen? More information may be revealed as the site investigations continue

Edited from LiveScience (22 September 2015)