xx <- seq(2667400, length = ncol(volcano), by = 10)
yy <- seq(6478905, length = nrow(volcano), by = 10)
image(xx, yy, t(volcano[,ncol(volcano):1]), asp = 1)
Created on 2020-05-10 by the reprex package (v0.3.0)
Coordinates above are in New Zealand Map Grid.