volcano.md

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.

https://www.linz.govt.nz/data/geodetic-system/datums-projections-heights/projections/new-zealand-map-grid-nzmg