slag heap 
noun British
A hill or area of refuse from a mine or industrial site: a rare plant which is only found on one slag heap in Cornwall...
- Standing on the flattened slag heap that served as the rocket launch site, he proudly sports a baseball cap emblazoned Rocket Boys Dad.
- In this play, the set also represents the urban slag heap of life, derelict it would seem except that it's not derelict.
- In 1966, a slag heap collapsed and engulfed a primary school in Aberfan, killing 144 people, including 116 children.