Halloween celebration at Walygator Park in France.

Halloween is a holiday celebrated each year on October 31, primarily in western countries, to mark the eve of the Christian feast of All Hallows' Day (Feast of All Saints), observed in honour of all the saints of the church. Historians believe that the tradition of Halloween or Hallowe'en (a contraction of “All Hallows' evening”) originated with an ancient Celtic festival where people lit bonfires and wore costumes to ward off ghosts. As such, to this day, the Halloween tradition continues, with people donning costumes, serving each other “trick-or-treat”, carving jack-o-lanterns, and generally engaging in festive gatherings to ward off all evil.