Anyone with a design sensibility cannot help but love dry stone walls. Alice Rawsthorn, writing in The New York Times, calls them “a dazzling example of design ingenuity.” As with any design that really resonates with us, dry stone walls are so intriguing because they do more with less, in this case, mortar.

“Dry stone” refers to the practice of carefully selecting and shaping stones and then puzzling them together so they interlock. As ancient as the Neolithic stone walls built to set boundaries as people evolved from hunting and gathering to farming, dry stone techniques have been used for buildings and bridges, as well as walls.

The practice continues today, with few alterations to techniques developed about 9,000 years ago. Mariana Cook in her book “Stone Walls: Personal Boundaries” shows and tells the fascinating history and continuing story of dry stone construction.

One example that didn’t make her book, but could have, is Butaro Hospital in Rwanda. Built with the help of MASS Design, the structure features dry stone walls. Architects as MASS trained local Rwandans in the ancient craft. They became the masons: hand-chipping volcanic rock and beautifully shaping all the pieces so they fit together and form two walls of the hospital.