The Trinity Knot, also called the Triquetra, is a symbol that Wicca shares with Christianity. It is a symbol that looks like three interlocking leaves. It may have originated with ancient Celtic or Irish cultures, but its history is elusive. In modern Wicca, the Trinity Knot is often said to be associated with the three most important elements of earth, water, and fire. In Christianity, it has long been used to represent the Holy Trinity; in ancient Norse religion and ancient Celtic religion, the symbol appears but its meaning is unclear.