"Made by the Milanese sculptor Camillo Rusconi between 1715 and 1723, this monument represents the pope giving his blessing, on top of an urn bearing a relief showing the promulgation of the Gregorian calendar in 1582, when October 4th was followed by October 15th." (Citation: http://stpetersbasilica.info/Monuments/GregoryXIII/GregoryXIII.htm )
Photographed using a GoPro Hero4