Researchers unlock 400-year-old shipwreck padlock from 1583

• Researchers have successfully unlocked a 400-year-old brass padlock from a 1583 shipwreck.
• The four-letter combination was found and used to open the lock.
• The lock was discovered in the sand near Port Talbot, part of a treasure hoard from the shipwreck.
• The discovery provides insight into the contents of the 1583 shipwreck.
• The unlocking of the padlock resolves a longstanding maritime mystery.