miles is a noun that is used to refer to a unit of measurement. Miles are a unit of measuring length and distance, and usually used to denote long distances, such as from one city to another.
1. I'm only five miles away from the station.
2. The expedition was miles from civilization.
3. Their destination was hundreds of miles away.
it is important to note that 'miles' in noun form is always just spelled as 'miles,' and never as 'mile's.'