Diablo 4 Heathen's Keep
The Heathen's Keep Dungeon is located in Hawezar, and after you complete will unlock the Aspect of Numbing Wrath. You will encounter Knights, Clerics, Vampires Monsters and should be able to clear Heathen's Keep at a speed.
Heathen's Keep Location
You can find the location of Heathen's Keep within the Dismal Foothills in Hawezar. After completing the Heathen's Keep, you will unlock the Aspect of Numbing Wrath.