Without double checking, I would say that it looks like Faustina the younger---the wife of Marcus Aurelius---the reverse deity I'd have to look up to 'refresh' my ageing memory. I assume it is a Sestertius. And it would date somewhere around 161-175 AD.
I agree with John: provincial of Faustina, probably Faustina II. The reverse appears to be a female deity or personification, standing right, probably feeding a serpent from a patera. I think the deity may be Hygieia. It may be possible to narrow it down further. Edited: Gerhard Rohde (Vcoins seller) has listed a boatload of Faustina II provincials in the last week. Maybe you can find a similar coin amongst his offerings. Roman Provincial Coinage Online is another good database which may reveal some matches. Try using the Identification Search (link) selecting Faustina II and Hygieia (or Salus).
The obvious answer is Pautalia, Thrace, which used the type but I can not justify the remains of the reverse legend as seen in the photo.
Interesting information about a hoard of Faustina II bronzes, from one of the Gerhard Rohde listings: "This coin is part of a large hoard consisting of 673 pieces Faustina II. plus 4 coins of Crispina. It hit the market abt. 15 - 20 years ago without any information on site or circumstances how it was found. The coins were not cleaned but show a uniformly shiny patina. Many are extremely worn. Still, all coins are attributed with special consideration of die varieties. Nobody knows why this hoard consists of Faustina II. coins only (the 4 Crispina coins might have been taken erroneously in because in a worn state, they like very similar to Faustina coins.)" 523 of the 673 coins were from Pautalia. The general appearance of your coin is similar to the coins of this hoard currently offered by Rohde. I agree with Doug that the "obvious" answer is Pautalia, Thrace-- very snake-heavy iconography, Asklepios and offspring (Hygieia is his daughter).
