Located in southern Africa, the remnants of Great Zimbabwe indicates a thriving urban center from the 12th to the 17th century.  This civilization, dominating trade, demonstrated a high-level of complexity. The structures reflect the importance of the ruler and the strictly stratified society.  Further, the construction of this political structure illustrates the high-level of construction knowledge.  Specifically, some of the walls still standing today reach over 10 feet and consist of bricks locked together without mortar.

On another note, the Zamani project is an excellent complement to the content I already teach about this African diversity in the modern era (see this clip from Africa's Great Civilizations - https://www.pbs.org/video/africas-great-civilizations-city-great-zimbabwe-africas-great-civilizations/ )