Jinling is the ancient capital of six dynasties, which means this place has been inhabited for a long time, and being an ancient capital indicates it has always been prosperous. This area with unfinished buildings might have once been home to many people.
Later it became a cemetery, became a temple, became the Pit of Thousand, etc., because of the environmental influences of this place, causing many people to die either naturally or unnaturally, leaving their souls like wandering ghosts in this world.
It's very likely these people retained their memories from when they were alive, remembering many things from their past, yet not realizing they are already dead.
Of course, maybe for various reasons, they cannot reincarnate normally, which is very possible.
