The origin of the mountain's name is explained in
Irish mythology. According to the tale, the hero
Fionn mac Cumhaill was sought after by many young women. Fionn stood atop the mountain and declared that whichever woman won a footrace to the top would be his wife. Since Fionn and
Gráinne were in love, he had shown her a short-cut and she duly won the race. The mountain was also known by the longer name , 'mountain of the fair women'. Another local explanation of the name is that from a distance and the right angle, the hill resembles a woman lying on her back. The plain from which the mountain rises was known in
Old Irish as (modern Irish , or ) or the Plain of Femen. In Irish mythology, one of the burial cairns is said to be the abode of the god
Bodhbh Dearg, son of
the Dagda. Fionn marries
Sadhbh, Bodhbh's daughter, on Slievenamon, and their son is the famous
Oisín. In one tale, Fionn and his men are cooking a pig on the banks of the
River Suir when an Otherworld being called Cúldubh comes out of the cairn on Slievenamon and snatches it. Fionn chases Cúldubh and kills him with a spear throw as he re-enters the cairn. An Otherworld woman inside tries to shut the door, but Fionn's thumb is caught between the door and the post, and he puts it in his mouth to ease the pain. As his thumb had been inside the Otherworld, Fionn is bestowed with great wisdom. This tale may refer to gaining knowledge from the ancestors, and is similar to the tale of the
Salmon of Knowledge. In
Acallam na Senórach (Dialogue of the Elders), Fionn,
Caílte and other members of the
fianna chase a fawn to Slievenamon. They come upon a great illuminated hall or , and inside they are welcomed by warriors and maidens of the Otherworld. Their host,
Donn son of
Midir, reveals that the fawn was one of the maidens, sent to draw them to Slievenamon. The
fianna agree to help Donn in a battle against another group of the
Tuatha Dé Danann. After a lengthy battle, Fionn compels their foes to make peace, and they return to this world. ==Cultural references==