Monte+Testaccio

Massive hill formed over shards of broken amphoræ.

From Wikipedia:

an artificial [|mound] in [|Rome] composed almost entirely of //testae// ([|Italian]: //cocci//), fragments of broken [|amphorae] dating from the time of the [|Roman Empire], some of which were labelled with //[|tituli picti]//. It is one of the largest spoil heaps found anywhere in the ancient world, covering an area of 20,000 square metres (220,000 sq ft) at its base and with a volume of approximately 580,000 cubic metres (760,000 cu yd). Monte Testaccio was not simply a haphazard waste dump; it was clearly a highly organised and carefully engineered creation, presumably managed by a state administrative authority.