Heartland

The Heartland is a world map, which was released during the 2.0 Patch, belonging to the rebels. It has a location known as the revel base that is unlocked for only a limited time and cannot be attacked. There will be, however, very rewarding rebel occupations. Some which will reward you rare chem vials.

Locations
Rebel base (quest only) :save Sargent Ramsey from this base and fight your way out with a free Firedrake!

Occupations
Rebel army - typical rebel army. Should be the average for a level 42 or so. Rebel army v2 - now has chemical units, but most of them aren't place in a very well mannered Showdown rebel army- Still hard given the 3 hero units, but you don't need to win to complete its corrosponding quest.