Halloween is a popular holiday celebrated on October 31 (the eve of All Hallows’ Day) with customs and practices that vary greatly by country. In the Celtic, Irish, Scottish, Welsh mythology, Halloween is known as Samhain and is a time when the ‘Gates’ between this world and the ‘Otherworld’ are opened and ghosts and monsters are set free. The origins of Halloween date back to the Celtic festival of Samhain, which was celebrated from the end of the harvest season to the beginning of winter. The event marked the end of summer and the beginning of winter, as well as the end of one year and the beginning of another. It was believed that on October 31st, the boundary between our world and the supernatural world was thrown open, giving spirits the chance to join the living for a night.