A gold coin of Valens (reign AD 364-378) was discovered at Alderney, one of the Channel Islands between France and England. Alderney was once the site of a Roman fortress. Artist depiction of the Roman fortress Modern remains of the fortress: https://www.bbc.com/articles/cpegg5397wlo
They may well have found a solidus but that one pictured is an ordinary AE3. If you blow up the first image you can make out that it's a Victory dragging captive type. The BBC fact checking department has been absent for a while. Last year they published the Sponsian "new emperor" article without blinking once. Pretty disappointing. Rasiel
I agree that the coin does not look like a Valens solidus. Too often the BBC relies on stock photos for their articles.