Probably the most powerful knot in the book . This design is a triquetra in it's simplest form it represents ( Mother Earth or the Triple Goddess ) showing affinity towards the world as it should be ( A Simply Thought ) and doubly so, this double triquetra by two interwoven parallel lines. These two parallel lines are used to protect one another , from without and within , representing one individual's life and his or her relationship to another loved one, interwoven yet separate. Each triquetra also represents the forces of nature: earth, air and water. Later the triquetra was interpreted as the Holy Trinity and yet a strength in spiritual bond. The interwoven lines promote strength of friendship and love. I first came upon it on the Donaghmore cross in the Innisowen Peninsula , Co.Donegal.