In 1965, archaeologists were carrying out a survey in Hubei province, China, four miles from the ruins of Jinan, capital of the ancient Chu state, when they discovered 50 ancient tombs. Inside one of the tombs, sealed in a near air-tight wooden box next to a skeleton, they found a rare and perfectly preserved bronze sword with scabbard.
Reference:
https://ancientoriginsmagazine.com/ancient-chinese-sword