The Ai-Ais/Richtersveld Transfrontier Park is a peace park, a single protected landscape stitched across an international line. It was formed in 2003 by joining Namibia's Ai-Ais Hot Springs Game Park with South Africa's Richtersveld National Park, the two halves divided only by the Orange River. In 2007, facilities at Sendelingsdrift opened so that visitors and residents could cross between the countries inside the park itself, with immigration posts on both banks of the river. The idea is older than the politics: this is one ecosystem, one stretch of succulent desert, and the animals and plants never recognized the boundary that maps imposed on it.

By rights, almost nothing should grow here. Parts of the park receive an average of just 68 millimeters of rain a year. Yet the Richtersveld is one of the most botanically rich arid regions on the planet, a place where more than 360 plant species can crowd into a single square kilometer. Giant quiver trees and tall aloes punctuate the rocky terrain, and the half-mens stands sentinel on the slopes. Much of this diversity survives on fog rather than rain, moisture that rolls inland off the cold Atlantic and condenses on leaf and stone. The succulents have learned to drink it. The result is a garden disguised as a wasteland, and one of the reasons UNESCO took notice.

In June 2007, the Richtersveld Cultural and Botanical Landscape was named a UNESCO World Heritage Site, and the wording matters: cultural as much as botanical. This land is owned and managed by the Nama, who have herded sheep and goats across it for generations and who move with the seasons in search of grazing. The Richtersveld is the last place on Earth where the Nama still build the haru om, the portable rush-mat house, a domed shelter that can be packed onto an ox and carried to the next camp. Their pastoral knowledge, accumulated over centuries, is itself part of what the World Heritage status protects. The half-mens trees they revere are not folklore set apart from daily life; they are kin, woven into the way the Nama understand their own long history in this country.

The park holds some of southern Africa's most famous ground. The Fish River Canyon, often called the largest in Africa, carves through the Namibian section in a series of immense switchbacks. Downstream, at Ai-Ais, hot springs surface from deep underground, a steaming reward at the southern end of the canyon's punishing hiking trail. And along the bottom of it all runs the Orange River, the green thread that both divides the two countries and binds the park together. From the dry uplands where the half-mens lean toward home, the land falls away to this single lifeline of water, and everything here, plant and animal and human, is organized around finding it.