Our idea for the map was a clocktower that showed the time in different planes, for those planescape-like cities with lots of portals, where busy folks are heading to work in the cities of flame and going for groceries in the verdant fey planes.
All the rest of the complex arcane-alchemical-eldritch machinery on the other floors are just there to power the planar clocks, account for interplanar time dilation, fight off demonic fungi that would attach itself to unguarded time-magic-artifices, harvest errant energy to power the clocks, and so on, you know, technical stuff.
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