sun stone

Ancient technology was more sophisticated than we think, modern people may not have expected it.
Technologies that seem to only be possible in modern times have existed since ancient times, proving the outstanding creativity of ancient people.
Solar stones - the secret to helping Vikings rule the sea for more than three centuries
As artisans who have created countless great ships, both sailors who have wavered over them, they, the Vikings ruled the North Atlantic waters from 900 to 1200.