Although definitive evidence for the construction date of Sheffield Castle has long eluded archaeologists, a small patch of burnt ground has now helped unravel the mystery, according to a Miami Herald report. Researchers from Wessex Archaeology uncovered the deposit on the side of the motte, or artificial hill, where the original castle once stood. They believe that it was created when builders lit a fire during initial castle construction. With help from Museum of London Archaeology and the University of Bradford, the team relied on a cutting-edge method known as archaeomagnetic dating to date the fire and therefore the castle's...