rookery

noun (plural rookeries)

• 1a breeding colony of rooks, typically seen as a collection of nests high in a clump of trees.
• a breeding colony of seabirds, seals, or turtles.
• North American term for heronry.

• 2a dense collection of housing, especially in a slum area: they congregate cheek by jowl in unwholesome rookeries chosen for cheapness and convenience