In Greek mythology, the Labyrinth (Greek λαβύρινθος labyrinthos, possibly the building complex at Knossos) was an elaborate structure designed and built by the legendary artificer Daedalus for King Minos of Crete at Knossos. Its function was to hold the Minotaur, a mythical creature that was half man and half bull and was eventually killed by the Athenian hero Theseus. Daedalus had so cunningly made the Labyrinth that he could barely escape it after he built it. Theseus was aided by Ariadne, who provided him with a skein of thread, literally the "clew", or "clue", so he could find his way out again. In colloquial English, labyrinth is generally synonymous with maze, but many contemporary scholars observe a distinction between the two: maze refers to a complex branching (multicursal) puzzle with choices of path and direction; while a single-path (unicursal) labyrinth has only a single, non-branching path, which leads to the center. A labyrinth in this sense has an unambiguous route to the center and back and is not designed to be difficult to navigate. Although early Cretan coins occasionally exhibit multicursal patterns, the unicursal seven-course "Classical" design became associated with the Labyrinth on coins as early as 430 BC, and became widely used to represent the Labyrinth – even though both logic and literary descriptions make it clear that the Minotaur was trapped in a complex branching maze. Even as the designs became more elaborate, visual depictions of the Labyrinth from Roman times until the Renaissance are almost invariably unicursal. Branching mazes were reintroduced only when garden mazes became popular during the Renaissance. Labyrinths appeared as designs on pottery or basketry, as body art, and in etchings on walls of caves or churches. The Romans created many primarily decorative labyrinth designs on walls and floors in tile or mosaic. Many labyrinths set in floors or on the ground are large enough that the path can be walked. They have been used historically both in group ritual and for private meditation.