Our project, NEST, reexamines traditional concrete casting through Additive Manufacturing (AM) techniques. It addresses the distress faced by birds in urban environments and the challenges posed in designing complex geometries. Through AM, we created reusable plastic formworks using CAD modeling (Rhino3D) and 3D printing, eliminating material waste and errors in fabrication. The result was topologically interlocking concrete blocks, forming a mortar-free wall assembly, serving a dual purpose—providing shelter for birds and supporting plant growth. Inspired by the high incidence of bird collisions in Chicago, our project envisions modular wall assemblies strategically placed along the coastline. These assemblies act as safe havens for migratory birds during their flight journey, addressing the impact of modernist architectural principles in Chicago. The biosphere bowls on the modules are designed to support plant growth in their upright position and shelter birds in their inverted position. Beyond their primary function, the modular wall assemblies reimagine urban spaces, adding architectural dynamism to various contexts. This project was entirely developed in-house during the Fall '23 semester at the University of Illinois School of Architecture, and this collage captures the intensive research process and iterative design studies undertaken to develop the final modules.