The face in the barracks wall

This photo shows the last surviving piece of the old city walls of Auckland wriggling across the University of Auckland campus and cutting the general library off from the commerce department. The Albert Barracks Wall was built by British soldiers between 1846 and 1850, as a defence against possible Maori attack in the aftermath of the 'Northern War' of 1845-46. The attack never came, and the twenty-odd acres of barracks enclosed by the octagonal fortification are now given over to office blocks, parkland, and snotty-nosed undergraduates.

The remaining section of the wall covers no more than fifty metres, and was long ago colonised by several species of weed. More curiously, a gargoyle seems to have grown from the ancient stones:

Does anybody want to own up?