A woman serving coffee at the Blue Nile Falls was wearing this coin, an Austrian thaler. First minted in Austria (of course) in the 1700's (you can see the date 1780 on the coin), it was commonly--but not exclusively--used as currency in Ethiopia even into the 20th century. Now worn as jewelry I guess. This coin was almost certainly not minted in 1780 since that date has apparently been stamped on all thalers since that time.