This chapter uses Cuban–Angolan internationalist solidarity to explore the role of Atlantic Ocean histories in the making of 20th-century Luanda. Focusing on apartment blocks designed and built during the 1970s and 1980s by Cuban experts in cooperation with Angolans, it shows how both the planning and everyday experience of these buildings mobilized and created networks of solidarity and sociality based in oceanic histories. As such, the chapter sheds light into the making of an Atlantic socialist world through built form, and how this shaped and continues to shape Luanda's cityscape.