What does Na-Nóg mean ?

We are always asked what does the word Na-nÓg mean. It comes from the fairy tale Irish legend ("Tir Na-nÓg") , which translates Land of Youth The legend of Tir Na-nÓg is one that most Irish people are familiar with and one that many of us wish was true! Tir Na-nÓg was an enchanted land where the beautiful Tuatha de Danann lived. According to Celtic mythology, the Tuatha De Danann were the last generation of gods and goddesses to rule Ireland and they were possessed with magical abilities and great skills in the Arts.
They were eventually conquered in battle but were allowed to stay in Ireland if they remained underground. From then on they became known as the Celtic fairies we read about in ancient myth. The story of Tir Na-nÓg is closely linked to the story of Oisin, one of the great heroes and poets of ancient Ireland. Oisin was the son of Fionn Mac Cumhal (pronounced cool) and he became a member of Fionn's band of legendary heroes, the Fianna. The Fianna possessed enormous courage, strength and skill in hunting and war and they also lived by a high moral code. One of the Fianna principles was to marry only for love - and not money! One day while out hunting, a beautiful maiden approached him. Her name was Niamh of the Golden Hair, one of the Tuatha De Danann and the daughter of Manannan, the god of the sea. Niamh chose Oisin to be her lover and live with her in
Tir Na-nÓg. They travelled through many strange and wonderful lands on her magic white horse until eventually they reached Tir Na-nÓg. There they were married and lived a long and happy life together in this enchanted fairyland. Nobody ever grew old or sick in Tir Na-nÓg and Oisin spent 300 years there without looking or feeling a day older!
But even the land of eternal youth couldn't banish memories and he began to miss his people and his home terribly. Niamh understood his need to visit the mortal world again and see his friends and she provided him with a fairy horse to take him there. She warned him however that he must not set foot on the earth – if he did, he would never be able to return. Oisin arrived back in Ireland to see that much had changed over 300 years! Fionn and his men were long dead and the Fianna were by now only legends. Oisin didn't like what he saw and decided to return to Tir Na-nÓg and his beloved Niamh. On his way back he came across some men trying to lift a heavy rock and bent down to help them.
Tragedy struck when he slipped from the saddle and fell to the ground. Oisin fell on mortal soil and was instantly transformed into an old blind man. He wandered Ireland for
many years before St. Patrick took him into his house and tried to convert him to Christianity. Oisin told St. Patrick everything about Fionn and the warriors of ancient Ireland and
Tir Na-nÓg. He eventually died without ever again setting eyes upon Niamh and Tir Na-nÓg.