Help Me Populate a Magical Exclusion Zone with Cool Locations!

My PCs are about to discover a map of a Mournland style exclusion zone and will soon go there on an expedition, only the events that destroyed it (and others like it) were hundreds of years ago. In my setting the magical heights of the old empires were never equaled (naturally). I need to draw the map so, I need stuff to populate it with!

Think Numenera style magical tech, but urban decay and anomalies, a la Stalker. I have trawled that old En World thread about the Mournland, so some entries here are taken from there.

So far I have:

• Crashed skyship
• Dry river bed which once fed the capitol
• Mutant creature herds (would love some stat block recommendations)
• Trench lines and fortifications which once defended the capitol
• Farm houses/villages, untouched, food still on table
• graveyard, graves adorned with 'dead-ringer' bells - all bells ringing, graves empty
• Abandoned walker-forts (siege engine automata)
• Roaming Demon-engines (possessed flesh/machine siege engines a la 40k)
• Microburst wildmagic storm country
• Glass fields
• Train line (pyramids in the ground, a la Eberron)

I'd love some more inspiration - huge mega structures and eldritch machines. What purpose might they have once served? What auxiliary infrastructure surrounds a lost magi-tech goblinoid city on the players' approach? I want it to scream hubris, excess, mystery, and stupefying power.

Thanks all!