Can't tell much from the photos, but in the top photo, if you rotate it to the right 90 degrees, I think the main design is a shield. The top right quadrant of the shield may be a lion? If you can figure out what is on the shield, that would probably at least tell you what country this is from.
I think Parthicus is right about turning it - think it may be a clipped one of these: Hungary Ferdinand I, r. 1526-1564 (1554) Kremnitz Mint, AR Denier, 15.82mm x 0.3 grams Obv.: FERDINAND· D·G·R· VNG· 1554·, Coat of arms Rev.: PATRONA· * ·VNGARIE, Madonna and Child, mintmark K B on either side What's the size?
