Navan Fort — known in Irish as Emain Macha — is one of the most important archaeological sites in Ireland and the legendary capital of the Kingdom of Ulster. The earthwork monument, about two miles west of Armagh on a hilltop with views across the surrounding countryside, has been occupied since at least 4000 BCE and was the ceremonial and political center of Ulster for well over a thousand years.
The site consists of a large circular enclosure with a massive mound at its center, formed in the final phase of occupation around 95 BCE when a huge timber structure was filled with limestone boulders and deliberately burned, then covered with earth. The reasons remain debated. The whole complex is surrounded by a bank and ditch in the non-defensive Irish style — prestige monument rather than fortress.
Emain Macha is the setting for the Ulster Cycle of Irish mythology, one of the great bodies of Celtic literature, including the stories of Cú Chulainn and the epic Táin Bó Cúailnge. The Navan Centre adjacent to the site has excellent interactive exhibits explaining the archaeology and mythology. The site itself is open year-round without charge; the centre has a modest admission fee.