He stands just a foot off the road beside an old stone fence. A five-foot section of the stone fence has collapsed, and Gerrow is piecing it together one stone at a time. He uses an assortment of ...

The goal? To build a 20 foot (6 meter) and 213 ft (65 m) long dry-stone wall as part of a park where the landscape was digitally planned, and the earth autonomously excavated. The coolest thing ...