Amer'dall Crystal

Amer'dall Crystal is a pylon, usually placed near the center of the map. Some maps, however, do not allow the placement of this structure.

Gameplay:
In the game itself this hostile structure serves the purpose of denying early rushes. If attacked, it sends a wave stunning all units nearby, and then dealing massive damage to them. There is a small cooldown between the waves.

After the Amer'dall Crystal being destroyed, a New Life Form is given birth on it's place.

Trivia:
Amer'dall Crystals are first seen in one of the SotV maps, namely Last Wasteland.