A Birds Nest.
Some birds to create shelter to protect and warm the growing family make nests that are created out of things collected from the locality and placed together to form a whole space. The cup nest: Straw, grass, mud...woven together. They choose the location deliberately; safe from predators, sheltered from rains and winds, not too far from food. Family-sized spaces in the gaps between elements in the natural landscape.
What about a nest for the city bird, would they collect trash, compost, recycling, shards of man-made materials, all found in the locality, situated in an out-of-the-way underpass corner not seen from the street, or on the roof of a high rise, between the roof door space and the satellites? Family-sized spaces in the gaps between elements in the built landscape.