St. Galgano was a 12th century knight who renounced his dissolute ways and became a hermit after seeing the archangel Michael. To signify his conversion, he plunged his sword into a rock, which received it like butter would. The cruciform hilt became the cross that he venerated in his hermitage.
Later, Cistercian monks built a monastery on the site. It has since been reduced to ruins, but the sword in the stone remains.
