http://digventures.com/2017/01/found-archaeologists-discover-3500-year-old-jewellery-workshop/
Not an empire or civilisation I had heard of (as suggested by the article)......
Seems a bit recent for Dilmun proper, as mentioned in the Gilgamesh epic. The article does place it at the tail end of Dilmun's existence (2100-1700 BC) and the thrust of the discovery seems to be that the subsequent 'dark age' assumed by historians never actually happened.