It is depicted as a supernatural realm of everlasting youth, beauty, health, abundance and joy. Its inhabitants are the Tuath Dé, the gods of pre-Christian Ireland. In the echtrae (adventure) and immram (voyage) tales, various Irish mythical heroes visit Tír na nÓg after a voyage or an invitation from one of its residents. They reach it by entering ancient burial mounds or caves, or by going under water or across the sea.(Wikipedia)