Burial cairns

There are two burial cairns on top of the hill, on either side of a small lake. The southern one is a large passage tomb, the highest surviving passage tomb in Ireland.^[11] In 1961, a team of archaeologists explored the site and set up a 30-person camp near the summit.^[12] The tomb's cairn is 30 m (98 ft) wide and 5 m (16 ft) high. The chamber inside is 3.6 m (12 ft) wide, with a corbelled roof up to 4.3 m (14 ft) high. It contained three large blocks of stone seemingly used as basins, and fragments of human bone. Some bits of worked flint and a barbed-end arrowhead were also found, "the meager remnants that survived the centuries of tomb raiding".^[13] The entrance is aligned with the setting sun on the winter solstice.^[14] Radiocarbon dating suggests it was built c.3500–2900 BCE.^[15] The smaller cairn to the north of the lake was built later, perhaps during the early Bronze Age (around 2000 BC).^[16] It contains two cist burials, with one containing bits of burnt bone; likely the remains of a single adult.^[17]

The two cairns were disturbed by American soldiers training there during World War II.^[18] Irish folklore holds that it is bad luck to damage or disrespect such tombs and that doing so could bring a curse.^[19][20] Today they are historic monuments protected by law. In recent years, volunteers have helped to repair the burial cairns under the supervision of an archaeologist.^[21]

Titus Oates Plot

Around 1680, religious persecution of local Irish Catholics heated up in reaction to Titus Oates' claims of a non-existent Catholic conspiracy aimed at assassinating King Charles II of England and massacring the Protestants of the British Isles. As a result, a Catholic priest named Fr. Mac Aidghalle was murdered while saying mass at a mass rock that still stands atop Slieve Gullion. The perpetrators were a company of redcoats under the command of a priest hunter named Turner. Redmond O'Hanlon, the outlawed but de facto Chief of the Name of Clan O'Hanlon and leading local rapparee, is said in local oral tradition to have avenged the murdered priest and in so doing to have sealed his own fate.^[22]

Fionn and the Cailleach

In the tale known as The Hunt of Slieve Gullion, Áine and her sister Milucra both seek after the legendary hero Fionn mac Cumhaill (Finn McCool). Knowing that Áine vowed never to marry a man with grey hair, Milucra secretly puts a spell on the lake atop Slieve Gullion, so that anyone who swam in it would become elderly. She tricks Fionn by asking him to fetch her golden ring from the lake, and he emerges as an old man with grey-white hair. His men, the Fianna, force her to give him a restorative potion from her cornucopia. Fionn's youth returns, but his hair does not return to its true colour.^[26] This is said to be the origin of his name, Fionn, meaning 'white'. In some versions of the tale, Milucra is revealed to be the Cailleach Bhéara (Calliagh Birra), an ancient goddess.^[27]

The names of several features on the mountain refer to the Cailleach Bhéara. The passage grave is known locally as Calliagh Birra's House and the small lake is called Calliagh Birra's Lough.^[28] Lower down, on a hillock called Spellick, is a rock feature called the Calliagh Birra's Chair. Locals would visit it at Lughnasadh and take turns sitting on the chair.^[29]

Cú Chulainn

Slieve Gullion is said to be where the legendary hero Cú Chulainn (Cuhullin) received his name and where he spent his childhood as Sétanta.

According to myth, the mountain is named after Culann the metalsmith. Culann invites Conchobhar mac Neasa, king of Ulster, to a feast at his house on the slopes of Slieve Gullion. On his way, Conchobhar stops at the playing field to watch the boys play hurling. He is so impressed by Sétanta's performance that he asks him to join him at the feast. Sétanta promises to join him after he finishes his game. Conchobhar goes ahead, but he forgets about Sétanta, and Culann lets loose his ferocious hound to guard his house. When Sétanta arrives, the hound attacks him, but he kills it; in one version by smashing it against a standing stone, in another by driving a sliotar (hurling ball) down its throat with his hurley. Culann is devastated by the loss of his hound, so Sétanta promises to rear him a replacement, and until it was old enough to do the job, he himself would guard Culann's house. The druid Cathbhadh announces that his name henceforth would be Cú Chulainn, "Culann's Hound".

In the Táin Bó Cuailnge, the nearby Gap of the North is where Cú Chulainn single-handedly fends-off the army of queen Méabh.^[30]