Jack of Harts

The Great Wall of Xin Shi isn’t actually a wall of course.  It does ring the planet, where day and night meet, but it isn’t a single building by any means.  It’s broken up by lakes and small oceans, and even on land it is more a collection of buildings crammed together.  Those buildings on the line itself are the largest and richest of course, towering over their lesser cousins.  The buildings on the edge of the habitable zone are the slums of Xin Shi.