The Sword of Goujian was discovered in 1965 in Hebei Province and is estimated to be around 2,500 years old. It is known for its unusual sharpness and incredible resistance to tarnish. The sword was found in a tomb along with a human skeleton and was sheathed in a wooden scabbard finished with black lacquer, which helped to preserve it.

The sword's chemical composition, mainly made of copper and with a high sulfur content, made it more pliant and less likely to shatter, as well as harder and capable of keeping a sharper edge. The video also provides a brief overview of the Spring and Autumn periods in Chinese history, during which the sword was likely made.