The Athena Tetradrachm is perhaps the most widely collected ancient coin and is a staple of any collection. The obverse of the coin shows the god Athena while the owl is considered her "mascot". This type was the first true international currency of the ancient world and represented about a week’s pay for ancient Greek soldiers.
An interesting tid-bit about this coin type is that they almost always have an incomplete head or crest on Athena’s helmet due to spacing limitation of the hand struck dies used on a smaller blank planchet. There are a few that have been dignified as being "full crest" but these are tremendously rare and hard to come by. 
My example from 440-404 BC is no different.