(CNN)For the first time in history over half the world's population live in cities -- more than 54% of us did in 2014. Mass urbanization is proving to be "the single most important transformation" the world is seeing in the 21st century, according to Jamal Saghir, director of sustainable development at the World Bank, and it shows no signs of letting up. By 2050, the U.N. predicts 66% of us will call a city our home. It is generally accepted that cities are the engines of economic growth, and nowhere are these engines firing harder, or populations growing faster, than in the developing world. With burgeoning higher education systems and enviably young workforces, African cities in particular are booming. Commended for their diversity, adaptability and enterprise, investors are taking note. Global auditing firm PwC has now quantified and ranked Africa's urban hubs in a new report listing the continent's top "Cities of Opportunity." With the caveat that only one city per country could be assessed, PwC set out ranking locations in terms of infrastructure, human capital, economics and society and demographics. North African cities dominated the top five, with Cairo claiming pole position, followed by Tunis, Johannesburg, Casablanca and Algiers. Analysts cited the age of North African cities as a determining factor, with strong infrastructure across the board, incubating an environment for human capital to thrive. However, sub-Saharan cities registered among the highest in terms of society and demographics, excelling in diversity and population growth, both useful when looking towards future investment. Indeed, the report also offered an alternative ranking, gauging the strongest trajectories in terms of investment. GDP growth, ease of doing business, attracting FDI, middle class and overall population growth all took precedent. Under these criteria, Cairo could only achieve a mid-table ranking and was the only city in the top 10 north of the Sahara. Dar es Salaam, Lusaka, Nairobi, Lagos and Accra made up the top five, suggesting a new generation of African powerhouse economies is waiting in the wings. That being said, one city's development does not preclude another's. What is certain is that the battle for economic dominance is on. Read this: Africa's 10 most prosperous countries . More from Marketplace Africa . Editor's Note: CNN Marketplace Africa covers the macro trends impacting the region and also focuses on the continent's key industries and corporations .
New PwC report has sought out the best cities for investors in Africa . North African capitals dominate, but there are signs that sub-Saharan cities will come into their own in the near future .