Two very different resolutions answer two very different questions about a growing African city: three decades of coarse Landsat imagery reveals the big picture of where a city has expanded, while a fine-tuned vision transformer extracts individual building footprints for planning at street level. This course builds both, using Accra, Kumasi, Lagos, Nairobi and Dar es Salaam — five of the fastest-growing urban areas on Earth — as running examples.