Following the aftermath of Jaeger and Kaiju combat, damage and contamination from the decomposing Kaiju body brought on from battles would leave the surrounding land uninhabitable for a time. As a result, the land is no longer considered hospitable or financially desirable.
The bodies of Kaiju left behind are harvested by scavengers and black marketeers for profit until nothing except its bones remains. Though depreciated, individuals who choose to re-inhabit the land and rebuild in an environment that co-exists with the remains of the Kaiju.
Hong Kong Bone Slum
In the aftermath of Reckoner's attack on Hong Kong in 2016, property values in the polluted areas plummeted, resulting in a shantytown that attracted crime and Kaiju Cultists. Many buildings are constructed in or around Reckoner's skeleton, its skull would later house a temple for worship.