UK £2. Just kidding. The obverse is too worn to tell anything. Post a picture of the reverse, the weight to the nearest 0.1g, and the diameter of the coin.
If I were forced to guess, I would say it was Roman, and based on a subjective examination of the portrait most likely from either Vespasian or his son Titus (they resemble each other, for obvious reasons). But unless there's some important feature on the reverse side that would allow a definitive ID, I don't think anyone can be certain. Some coins are not attributable to a specific (country, era, emperor, etc.) and we just have to live with that uncertainty.
