The Festival of Samhain marked the end of the Celtic year and the beginning of the new one and as such can be seen to the equivalent of New Year's Eve. We have seen how the Celts believed that night preceded day and so the festivities took place on the Eve of Samhain. There is no doubt that that this festival was the most important of the four Celtic Festivals. Samhain was a crucial time of year, loaded with symbolic significance for the pre-Christian Irish. The celebrations at Tlachtga may have had their origins in a fertility rite on the hill but it gathered to itself a corpus of other beliefs which crystallised at the great Fire Festival.