Encounter set:
Assault on Osgiliath
Osgiliath.
Travel:
Reveal the top card of the encounter deck and add it to the staging area to travel here.
Forced:
After the player who controls The King's Library lets an attack go undefended, return The King's Library to the staging area.
"For that is the ruin of Osgiliath on either side of Anduin, which our enemies took and burned long ago." - Beregond, The Return of the King