THE SCENE: The caves on the island of Visingsös are considered so full of dangerous magic that exploring them is forbidden by the same type of law that forbids suicide.
THE TEXT: Among the Eastern Götar is a very large fresh-water lake called Vättern with a pleasant, longish island at its very centre, containing two parish churches. Under one of them is found a cavern, immeasurably deep, with a long underground entrance and exit. Only for vain display and curiosity do men go down into this cavern, equipped with lighting lamps and balls of twine to enable them to find their way back. Their chief purpose in doing this is to gaze at a certain wizard named Gilbert who, by means of magic was in very ancient times overcome and bound fast by his master, Kettil, to whom he had ventured to be insolent. It was done like this: a small staff, engraved with certain Gothic characters, was thrown towards him by his master, and when Gilbert caught it in his hands he remained fettered and unable to move. Nor could he free himself when he applied his teeth to it, for it was as if they were stuck together with an adhesive pitch, nor with his feet when, on the crafty advice of his master, he tried to use them.
Although many would-be spectators of a heedless nature hasten with compulsive wonder to gape at him, they are not rash enough to approach too closely, in case their breathing should be hampered and their throats blocked by the stench of the cave’s poisonous vapours, and they should die of suffocation. They are kept away also by earth walls and obstructions put up by local people, who fear that, scorning danger and acting insanely, these folks may go in never to emerge. As well as these precautions, care has been taken by passing a very strict law, like the one that deals with people who have tied to commit suicide. It decrees that those who realize the danger should not incite others who are unacquainted with them to go and examine this kind of spectacle, or take inside any whose appetites have been whetted.
– A Description of the Northern Peoples, Olaus Magnus, 16th Century AD
