She who is in Babylon, chosen together with you, greets you; and so does Mark, my son.
The words "in Babylon" immediately bring many things and places to mind. The possibilities are at least three: The Chaldean capital, Rome, or a small village in Egypt. The basic rule of interpretation requires that we rely upon the obvious. Peter wrote this letter while in Babylon upon the Euphrates. The people of Pontus would have so understood it.