The Dorsey Ramparts are an extensive earthwork which runs through the south of County Armagh, at the edge of the Ring of Gullion. They were known in Irish as Na Doirse, meaning 'the gateways', giving a name to the townland, Dorsey. Locally the ramparts are known as 'the Walls'.
are said to have been a fortified frontier post to the kingdom whose capital was Emain Macha (Navan Fort), blocking an important historic route into South Armagh. It was built at a time when the power of the Kingdom of Ulster may have been at its strongest, around 100 BC. Some time later Ulster was threatened from the south and it is speculated that Dorsey may have been incorporated into a more extensive defensive system known in Monaghan and further west as the Black Pig's Dyke.
Dorsey is one of the few monuments in Ulster which have been confirmed as Iron Age in date. It is a group of linear earthworks with a perimeter of two and a half miles, enclosing an area of 300 acres.