I’ve hiked and driven these quiet lanes so many times over the years that I sometimes take it for granted how much this part of Northern Ireland is soaked in history and mythology. Slieve Gullion – literally, mountain of the steep slope in Irish – is the eroded remains of a Paleocene volcano. It lies at the heart of the Ring of Gullion, which is itself a topographical curiosity only recently understood: an ancient ring dyke. (With the collapse of an active volcano’s caldera, a concentric ring of fault lines radiate outwards. Magma is extruded through these fractures to create mountains which are a geologically helter-skelter composite at their surface. Here the mix is molten granite with igneous rock from the Silurian period some 400 million years ago.) It’s the highest point in County Armagh, and on that rare clear day offers views as far away as Dublin Bay and Wicklow. At the top of the mountain are two cairns on either side of a small lake. The southern one is the highest surviving passage grave in Ireland – radiocarbon dating suggests it was built circa 3000 BC – and its entrance is aligned to the setting sun of the winter solstice. According to legend, however, Slieve Gullion is named after Culann, the metalsmith. And it is here that the legendary warrior Sétanta spent his childhood and received the name Cúchulainn. Culann invited Conchobhar mac Neasa, King of Ulster, to a feast at his house on the slopes of Slieve Gullion. On his way, Conchobhar stopped at the hurling field and was so impressed by Sétanta’s playing that he asked him to later join him at the feast. Conchobhar went ahead, but he forgot about Sétanta, and Culann let loose his ferocious hound to guard the house. When Sétanta arrived the hound attacked him, but he killed it by driving a hurling ball down its throat with his hurley. Culann was devastated by the loss, so Sétanta promised to rear him a replacement, and until it was old enough to do the job, he would guard Culann’s house. Henceforth he was known as Cúchulainn, or Culann’s Hound. But that’s just the beginning for young Cúchulainn, who will later single-handedly defend Ulster against the invading Connacht armies of Queen Medh at the nearby Gap of the North and take his place as Irish literature’s greatest mythic hero. All in a day’s hike, as they say.