Comment by Imnimo

It's also interesting to look at what happened in Luanda. During the civil war, a large portion of the population fled to the capital for safety. The city went from half a million in 1970 to ~9 million today. Now downtown Luanda is one of the most expensive places in the world to live, and the city is surrounded by endless stretches of slums that are visible on satellite maps.

They are making progress on building new housing, but it's a very uphill battle.