The Petrifying Well, Mother Shipton's Cave, Knaresborough, England. The water is so rich in minerals it can transform objects into stone within days and it was believed to have miraculous healing powers. The side of the well looks like a giant's skull. This well is the only one of its kind in England and is made of two types of rock - tufa and travertine. It takes between three and five months to petrify a teddy bear.