Just Cause player: Just grapple up to that area.
Zelda player: Just find a Roc Feather.
Assassin's Creed player: Just run up the wall and climb into that area, it's not that hard.
Dishonored player: What, you haven't unlocked Blink yet?
Half-Life player: Stack boxes to make a staircase up to that area. Also, enemies won't be able to attack you there, so you can fire down at them with impunity.
Fallout player: There is probably loot up there.
Borderlands player: There is definitely loot up there.