Ruined Watch-tower
The Weather Hills Nightmare #16 (x3)
Location
3 (4)
Arnor.   Ruins.  

While Ruined Watch-tower is in the staging area, it gains:"Forced: When an Orc enemy is revealed, each player must deal 1 damage to a character he controls.

While Ruined Watch-tower is the active location, each enemy gets +3Defense