Home to nearly 240 million people, Nigeria is Africa’s most populous country. About twice as many people live there as in Ethiopia, Egypt, the Democratic Republic of the Congo, and Tanzania—the next four largest—and demographers expect the country to grow by another 130 million residents by 2050.
A substantial portion of that growth will occur in Lagos, a megacity of 17 million on the southwestern coast that could become the world’s most populous city by 2100, according to some projections. But Nigeria is also home to 85 other “secondary cities” with 100,000 or more people. It’s in these smaller cities that urbanization specialists expect to see some of the fastest growth rates in Africa and the world in the coming years, explained Jody Vogeler, a Colorado State University researcher whose lab uses satellites to study urbanization trends in Africa.
Benin City is a textbook example of a rapidly growing secondary city, said Vogeler. The city was once the seat of government for the historical Kingdom of Benin, a precolonial West African state that prospered between the 1200s and 1800s and built some of the world’s largest earthworks. In recent decades, as part of Nigeria, the city’s population boomed from about 350,000 in 1980 to more than 2 million in 2025.
As the population grew, remote sensing experts tracked an accompanying surge in developed land. The ETM+ (Enhanced Thematic Imager Plus) on Landsat 7 captured the image above (left) in 2002, when the population was roughly one million. By the 2020s, the developed land had nearly doubled as vegetated areas in the city declined by more than 650 square kilometers (250 square miles). The OLI-2 (Operational Land Imager-2) on Landsat 9 captured the other image (right) on January 11, 2025.
The darkest green areas surrounding the city are Nigerian lowland forests, a type of rainforest with sever …