On a recent trip through Dulles, I went to the Air France Business Class Lounge. This lounge is located near A21 in the Dulles Airport. I was able to access it utilizing my Priority Pass Select membership that I have from my Platinum Card® from American Express.
It is a great place to stop by on a domestic flight and grab a beer, or a glass of wine and enjoy a quiet place. There is plenty of seating except when all the international flights are leaving at night.
This is a great lounge to check out next time you are going through Washington Dulles International. If you have the Platinum Card® from American Express, you can enter this lounge for free.