Castle Island is a peninsula in South Boston on the shore of Boston Harbor. In 1928, Castle Island was connected to the mainland by a narrow strip of land and is thus no longer an island. It has been the site of a fortification since 1634, and is currently a 22-acre (8.9 ha) recreation site and the location of Fort Independence.

South Boston is a densely populated neighborhood of Boston, Massachusetts, United States, located south and east of the Fort Point Channel and abutting Dorchester Bay. It has undergone several demographic transformations since being annexed to the city of Boston in 1804. The neighborhood, once primarily farmland, is popularly known by its twentieth century identity as a working class Irish Catholic community. Throughout the twenty-first century, the neighborhood has become increasingly popular with millennial professionals.