In this lecture Dr. David Pacifico presents his research on ancient urban neighborhoods in Peru and compares them with the society and cultures of modern urban neighborhoods. Specifically, this lecture details social diversity, urban economies, and politics in a commoner neighborhood at El Purgatorio, capital of the Casma culture in 13th century Peru. From the capital, the lecture moves outward to present preliminary findings from ongoing research on hinterland communities around El Purgatorio. Finally, David explores the meaning of these findings with respect to our understanding of modern urban neighborhoods and cultures.