The Cretan (or Minoan) labyrinth is the oldest form of labyrinth. It comes from the ancient Goddess-centred Minoan civilization which once flourished on the island of Crete in the Mediterranean Sea. This labyrinth is sacred to the Great Goddess, as evidenced by its circular shape (a central symbol of the Divine Feminine). The four rounded turns within the labyrinth are known as "the breasts of the Goddess."
How does this labyrinth's unicursal nature fit with the ancient Greek myth of the Minotaur? The Cretan priestess Ariadne gave a ball of red yarn to the Athenian hero Theseus so he could trace his way into the labyrinth, kill the Minotaur at its centre and then safely find his way out again. That's a description of a maze, not a true labyrinth.
I think the myth we know today is a later patriarchal version interpreting (and distorting) much older symbolism. We know that bulls were sacred to the Goddess in ancient Crete. "Minotaur" means "moon bull" so it was probably a revered symbol of the Divine Feminine in Crete's early days. In the myth's patriarchal version, the Minotaur becomes a symbol of death and evil which must be slain. Scholars also believe that Ariadne was originally the Great Goddess Herself but was downgraded in the patriarchal myth to simply being the daughter of the King and a priestess in the temple. She betrays her people and her religion to help Theseus, who callously uses and deserts her.
So, given these later patriarchal distortions, it's not really surprising that a unicursal labyrinth gets recast as a multicursal maze. It moves the plot along, creates suspense and sets the context for Ariadne's betrayal. In fact, this Greek myth as a whole may be understood as a metaphor for the ascendancy of patriarchal culture over the Goddess-centred culture which preceded it.
Now that the Divine Feminine is being actively revered again in the western world, walking Her labyrinth has become a popular expression of Goddess spirituality and devotion among pagans.
We tread Her sacred path once more.