Got it, it's an AR Tetradrachm / sela
it's a greek design from emperor Nero
the front side has the head of Nero and is written "ΝΕΡΩΝ ΚΑΙΣΑΡ" in Greek which means Nero Ceasar.
On the other side is written "ΕΤΟΥΣ" which means year.
And that thing written on the left next to the eagle is the date, the coin was probably created.
Here's a link:
http://www.tantaluscoins.com/coins/22304.php