Complex sentence: The square, Place Saint-Gervais, located at the foot of the steps outside the church, was, for a long time, called the Crossroads of the Elm: since the Middle Ages, a venerable monarch of an elm, grew at its center.
Split into simpler sentences: The square, "Place Saint-Gervais", located at the foot of the steps outside the church, was, for a long time, called the "Crossroads of the Elm". Since the Middle Ages, a venerable monarch of an elm, grew at its center.