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 ...

A low stone wall nearly a kilometre long has been found 21 metres below the surface of the Baltic Sea off the German coast. The wall is thought to have been built around 11,000 years ago to ...