This is a silver tetradrachm from Ancient Greece - this is from the Thracian islands : Thasos. I think this is from circa 146 BC. On the obverse is a young Dionysus with wreath whilst on the reverse is Hercules standing whilst resting on a club.
It weighs over 16g as per the photo. This item is in the category "Coins\Coins\Ancient\Greek". The seller is "hughes-browne" and is located in this country: GB. This item can be shipped to United Kingdom.