This highly curious combination of grotesque mask, given a distinctly Aztec appearance, and sphere topped by a castle has no clearer explanation than many of the other features of the Sacro Bosco. The combination may refer again to Vicino’s distraught, disturbed state at the loss of Giulia; the sphere (sfero), as Lang (1957) suggests, can traditionally, via a pun, represent hope (spero), particularly hope for love.