I've restarted my languishing Greyhawk mapping project

[AdmundfortGeographer]

Where did you find those keeps you placed near the Dim Forest? Are those from an adventure?

The ones around Hochoch? Those would be a legacy of the Greyhawk Wars and then Living Greyhawk development. LG took the timeline a few years after the Greyhawk Wars, had forces from Gran March liberate Hochoch from the occupying armies of the giants.

The LG campaign had a series of protective forts built around Hochoch. I found the forts on multiple Geoff Triad maps.