Halloween is a cool holiday on October 31st. People love it in the United States and Canada, but it started in Ireland, Scotland, and England (The Celts) a long time ago. On Halloween, you get to wear fun or scary costumes, go trick-or-treating to collect candy, and have parties with games like bobbing for apples and spooky haunted houses. We also carve pumpkins into funny faces or scary ones, and we call them jack o'lanterns. Some other countries celebrate Halloween too, but it's the most exciting in the United States.