Nightfall area unlocking

Istan

 * Rally the Recruits (Tutorial) or Take the Shortcut (Skip Tutorial)
 * Into Chahbek Village (unlocks Chahbek Village (Location), recruits Koss)
 * Quiz the Recruits
 * Chahbek Village (Mission) (unlocks Kamadan, Jewel of Istan)
 * Primary Training
 * Honing your Skills
 * Secondary Training
 * Choose your secondary profession
 * Leaving a Legacy (recruits Dunkoro)
 * The Honorable General
 * Signs and Portents (unlocks Jokanur Diggings (Mission), recruits Melonni)
 * Jokanur Diggings (Mission)
 * Isle of the Dead (unlocks Beknur Harbor)
 * Bad Tide Rising (also unlocks Student Jin and Student Sousuke)
 * Special Delivery
 * Big News, Small Package (recruits Tahlkora)
 * Following the Trail (unlocks Blacktide Den (Location) and Blacktide Den (Mission))
 * Blacktide Den (Mission)
 * The Iron Truth
 * Trial By Fire
 * War Preparations (Ghost Reconnaissance), War Preparations (Recruit Training), War Preparations (Wind and Water)
 * The Time is Nigh (unlocked nothing during the Guild Wars Nightfall World Preview Event, presumed to unlock Gandara after release)