Researchers at ETH Zurich have developed an autonomous excavator that can construct dry-stone walls using locally sourced materials. The excavator, called HEAP, uses sensors and machine vision to scan and grab large stones, and an algorithm to determine the best position for each stone. The team built a six-metre-high and sixty-five-metre-long dry-stone wall using this technology. The wall is part of a digitally planned and autonomously excavated landscape and park.