Diablo 4 Ancient Reservoir
The Ancient Reservoir Dungeon is located in Hawezar, and after you complete will unlock the Aspect of Ancestral Echoes. You will encounter Demons, Skeletons Monsters and should be able to clear Ancient Reservoir at a speed.
Ancient Reservoir Location
You can find the location of Ancient Reservoir within the Rotspill Delta in Hawezar. After completing the Ancient Reservoir, you will unlock the Aspect of Ancestral Echoes.