Did you know that a lot of the American traditions for Halloween like the carved pumpkin, dressing in costume and calling door to door, were taken from Irish traditions. It died out here, but isnow again returning again due to American influences on TV, the funny thing is that people don't realise that their history.
Halloween was a Celtic festival called Samhain or the feast of the dead, though there is traditions in other cultures celebrating the end of the harvest.
On this night in Celt's believed that the dead walked around amongst the living, to avoid detection Irish people dressed up in costumes of the spirits and faeries so that they would not be carried away to the otherworld. If they were detected they also had the backup of taking the dust from their shoes and throwing it at the spirits. There was a tradition of leaving out gifts of food for the fairies, during Samhain people dressed up called around to neighbours house and got those gifts.
The Jack'o'Lantern has its roots here too, Jack was by all accounts a wicked miserly evil man who was destined for hell. One night he had stolen from his neighbours and making his escape met the Devil on the road. The devil was there to collect his soul, but Jack being cunning managed to trap the devil with a cross so that the Devil lost his power. In order to gain freedom the devil said that Jack would never go to hell and when he died he was not sent to hell, yet he was too evil to go to heaven. The Devil laughed at him and threw an Ember of coal from the fires of hell at him to give him light. Jack placed this into a hollowed out turnip and now wanders the roads of Ireland.
Other stories that have a celtic origin are the headless horseman, the borrowers and swanlake, but stories for another day.
Happy Halloween/Samhain