In the dry stretch between Africa’s Sahara Desert and tropical forests, the landscape has been slowly changing, giving new signs of life in places where there was previously none, or where there once was before the effects of climate change took hold. These are the building blocks of the Great Green Wall, a vision conceived some 30 years ago and formalized in 2007 to create a grand mosaic of green and productive landscapes across the vulnerable Sahel region – linked forests, shrublands, forested farms, grasslands and wetlands stretching 8,000 kilometers across the entire width of the continent. It is one of the most ambitious landscape restoration efforts in history, yet it is shrouded in mystery. How much of the Wall stands already, and where? Is completion realistic, and who will fund it? The odds are great and the stakes are high, with civil conflict persisting in certain regions and a population boom looming on the sandy horizon. In this three-part series, people who have watched the construction process closely so far offer stories of hope and the hard truths of the Great Green Wall.