Castle Hill is a neighborhood located in the southeast section of the borough of the Bronx in New York City. Its boundaries are Waterbury Avenue and Westchester Avenue to the north, Westchester Creek to the east, the East River to the south, and White Plains Road to the west. Unionport is a subsection of Castle Hill, typically considered north of Lafayette Avenue.

The New York City Housing Authority (NYCHA) is a public development corporation which provides public housing in New York City, and is the largest public housing authority in North America. Created in 1934 as the first agency of its kind in the United States, it aims to provide decent, affordable housing for low- and moderate-income New Yorkers throughout the five boroughs of New York City. NYCHA also administers a citywide Section 8 Leased Housing Program in rental apartments. NYCHA developments include single and double family houses, apartment units, singular floors, and shared small building units, and commonly have large income disparities with their respective surrounding neighborhood or community. These developments, particularly those including large-scale apartment buildings, are often referred to in popular culture as "projects."