The origins of Halloween come from ancient Celtic traditions. The Celts, who lived in Europe over 2000 years ago, celebrated the end of summer on November 1st. They believed that ghosts visited the living on October 31st, so they dressed in costumes to avoid being recognized by spirits. Today, many countries remember the dead on November 1st, called All Saints Day or All Hallow's Day. October 31st is called All Hallow's Eve or Halloween. Halloween traditions originated in Ireland and Scotland, where people carried turnips lanterns and gave food to spirits, which later evolved into trick-or-treating.