Oyster middens—huge heaps of discarded shells—like this one in New Jersey have been a rich building resource in U.S. history, providing raw material for making mortar. Photo 3 of 9 in RM-3 Episode Five: Clams

RM-3 Episode Five: Clams

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Oyster middens—huge heaps of discarded shells—like this one in New Jersey have been a rich building resource in U.S. history, providing raw material for making mortar.