ARLAN's HIDEAWAY
THE BONE PIT
THE BONE PIT MINES (BONE PIT): You can only access this location during the side quest
"Cave Crawling"
DANK CAVE (WOUNDED COAST): You can only access this location during the side quest
"Forbidden Knowledge"
DARKTOWN
DUPUIS ESTATE: You can only access this location during the main quest
"Prime Suspect"
GALLOWS DUNGEON (DARKTOWN): You can only access this location during Ander's companion quest
"Dissent"
HIGHTOWN: During the main quest
"Demands of the Qun" make sure to search the corpse opposite of the lady in green
BEFORE entering the Viscount's Keep!
HOLDING CAVES: After completing the companion quest
"Talk with Fenris" travel to any Free Marches location with an
elf in your party and you will be ambushed by Tevinter Slavers and begin the quest
"A Bitter Pill." After leaving the area you can travel to the Holding Caves.
THE KILLER'S LAIR: You can only access this location during the main quest
"All That Remains" but make sure to collect the Orichalcum
BEFORE confronting the killer!
LOWTOWN: You can only acquire the Rock Armor potion at night by searching the pile of rubble beside Gamlen's House.
ROTTING CAVE (THE BONE PIT): You can only access this area during the side quest
"Forbidden Knowledge"
SMUGGLER'S CUT (DARKTOWN): You can only access this area during the main quest
"Blackpowder Courtesy"
SUNDERMOUNT
SUNDERMOUNT CAVERNS
VARTERRAL HUNTING GROUNDS: You can only access this location during Merrill's companion quest
"Mirror Image"
THE WOUNDED COAST