Mt. Slagmore is the unofficial name for a hill in the Coal District which was created during the late 19th and early 20th centuries by the steel industry in Gotham. Under pressure from the state government, the companies stopped piling up the slag in one place inside the city and began to have to taken out of town by barge right after the Great Fire of 1911. Since then, the hill has been covered in soil and heavily planted with trees and other plants (to varying degrees of success).

It is rumored that there large caves or cavities all throughout the hill, and its soundness is less than securely tested. The general public is not permitted to use the hill for recreation or idle larks. There is a fence around the whole place and a few bored watchmen wander about the perimeter.