At the end of which season the daughters of Airitech would come out of the Cave of Cruachan every year?
Samhain Samhain (pronounced or , ] ) is a Gaelic festival marking the end of the harvest season and the beginning of winter or the "darker half" of the year. Traditionally, it is celebrated from 31 October to 1 November, as the Celtic day began and ended at sunset. This is about halfway between the autumn equinox and the winter solstice. It is one of the four Gaelic seasonal festivals, along with Imbolc, Bealtaine and Lughnasadh. Historically, it was widely observed throughout Ireland, Scotland and the Isle of Man. Similar festivals are held at the same time of year in other Celtic lands; for example the Brythonic Calan Gaeaf (in Wales), Kalan Gwav (in Cornwall), and Kalan Goañv (in Brittany).
Tír na nÓg In Irish mythology and folklore, Tír na nÓg (] ; "Land of the Young") or Tír na hÓige ("Land of Youth") is one of the names for the Otherworld, or perhaps for a part of it. It is depicted as a supernatural realm of everlasting youth, beauty, health, abundance and joy. Its inhabitants are the Tuatha Dé Danann, 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.