You know how these levels are always on beaches? Other transitions from land to water are possible. This is Zakynthos, Greece. It demonstrates what I think should be done. Why not use steep seaside cliffs with scrubby vegetation? Do like AIZ and start from the basics, ignoring the fact that GHZ and EHZ were in one type of location on the coast. As the Zone gets closer to the end, the vegetation gets thicker, until you're in a GHZ-alike. Or, better yet, do the opposite- have GHZ4.0 slowly transform into a barren land of stone.