The fort, built c 1100 BC, was by turns a sacred site and a defensive structure surrounded by a ditch. It was believed by many to be Emain Macha, the legendary capital referred to in the Ulster Cycle, even if the site was already occupied well before the Celts arrived. Multimedia presentations in the Visitor Centre shed light on the work of archaeologists, and an exhibition shows a number of finds unearthed on site.