The walls are traditionally controversial. For the most part, your goal is to separate people, preventing the ones you don't want from mixing with the ones you do.
But a huge wall being built in Africa is motivating people in 20 countries to join hands for a large-scale project for the common good. The Great Green Wall is an ambitious plan to grow a thicket of drought-resistant trees on some 6,000 miles (8,000 kilometers) of land at the southern tip of the Sahara Desert, a region known as the Sahel. It runs across the continent, from the Atlantic Ocean to the Red Sea.
The area was once green and mostly covered in grasslands and savannas. But persistent droughts have changed its makeup. Now, "More than anywhere else on Earth, the Sahel is at the forefront of climate change and millions of people are already facing its devastating impact," according to the project's website.
The area is dry and barren, and as a result, there is a lack of food and water, and increased migration as people seek better places to live, and conflicts arise over dwindling natural resources.
After years of working on a solution, leaders from 11 African countries joined the initiative in 2007. Today, there are more than 20 countries involved.
The Great Green Wall covers 780 million hectares of arid and semi-arid lands, and the area is home to 232 million people, according to the Food and Agriculture Organization of the United Nations.
Between all, they make an impact
Children join men and women of all ages to plant mostly drought-resistant acacias, as well as orchards full of vegetables and fruits. In just over a decade, the project is 15% complete.
As the project enlivens the arid landscape, the trees are having an impact on more than land degradation and desertification in the region. Not only is life returning to earth, but the millions of people who live there have found food and water security, greater well-being, more jobs (including promoting gender equality, as women have also found work) and a reason to stay.
As the project develops, research institutions, grassroots organizations, scientists, and even tourists have visited the area. As Atlas Obscura points out, this influx "has also drawn attention and resources to an underserved region where aid is scarce and doctors are not available to populations in need."
Changing the future
When finished, the Great Green Wall will be three times the size of the Great Barrier Reef. As the group symbol indicates, the wall runs from coast to coast. (Photo: Great Green Wall)
Once completed, the Great Green Wall should be the largest living structure on the planet, three times the size of the Great Barrier Reef.
"There are many world wonders, but the Great Green Wall will be unique and everyone can be part of its history," said Dr. Dlamini Zuma, chairman of the African Union Commission, in a statement on the project website. "Together, we can change the future of African communities in the Sahel."