The fact that is free is not exactly what's new. iBlueYonder's Heron's Nest for P3D is also free. What's really amazing is that we finally have a scenery for X-Plane, by Bill Womack!
Bill is a legend in the flight simulation community and his work is among the most amazing scenery we have seen for P3D. Having the ability to have his work also on X-Plane is like a dream come true.
Where to get iBlueYonder's Heron's Nest for X-Plane
You can get it here (again, for free!)