Amon Forn
The Lost Realm #26 (x1)
4 (6)
Arnor.   Ruins.  

Immune to player card effects.

While Amon Forn is the active location, it gains:

Forced: After an Orc enemy is added to the staging area, it makes an immediate attack against the first player.

The players cannot win while Amon Forn is in play.