Oisin in Tir na nOg
Oisin, was a great warrior and son Finn and Sadbh(the deer goddess). One day, he and his father were hunting when they saw a great white cloud and from it wrote a beautiful woman riding a white stallion. It was Niamh Cinn Oir, she told the men who she was and informed them her father was king of Tir na nOg, the Land of Eternal Youth.
She invited Oisin to join her and visit her country. He could not refuse and jumped on the stallion behind her. Along the way Oisin encountered many strange and beautiful things he had never seen in Ireland. Once there, there were even more beautiful and wondrous things for him to discover. The land was filled with life and beauty, everywhere he looked. This inspired Oisin to write great poems, of which Niamh was very fond. They quickly became deliriously happy lovers and lived in the lap of luxury.
They had two sons and a daughter and that only added to their joy. For years they lived happily. Then Oisin began to dream of Ireland and told Niamh he wished to return home to see his father. Niamh was wondered for him, but the white stallion appeared instantly, already saddled. As he prepared to leave, Niamh warned him not to dismount the horse.
Oisin found Ireland quite different than he remembered, the people were smaller and there were less trees. Where his father's castle once stood, now only ruins remained. He soon discovered 300 years had passed in what he felt only a decade. Riding through the countryside he saw some men trying to lift a large stone in a graveyard. He could not understand how they could be so weak, so he jumped down from the horse to help them. At that time, he lost his youthfulness and became a shriveled old man and died. They had no idea who he was, and buried him right there.