1. Ancient times (around the 3rd century AD) to the 17th century
    Mysteries & Phenomena ★★★★★ Egypt (Alexandria)

    Alchemy

    An art and philosophy from ancient to early modern times that sought to turn base metals such as lead into gold and to make an elixir of immortality. Born in Alexandria, Egypt, it developed in Europe by way of the Islamic world. It never achieved its goals, but its laboratory techniques became the foundation of modern chemistry.

  2. Ancient Celts (modern form 19th–20th century America)
    Mysteries & Phenomena ★★★★★ Ireland and Scotland (Celtic)

    Halloween

    A festival held on October 31. Its origin is said to be "Samhain," celebrated by the ancient Celts at the end of summer, when the spirits of the dead and monsters were thought to return to this world. Jack-o'-lanterns, costumes and trick-or-treating spread mainly in America.