We'll try to keep this area up to date with a list of open zones. Hopefully each will have its own wiki page to document maps and uniqueness.
Ak'Anon
Befallen
Blackburrow
Butcherblock Mountains
Clan Crushbone
Dagnor's Cauldron
East Commonlands
East Freeport
East Karana
Erudin
Erudin Palace
Erud's Crossing
Everfost
Gorge of King Xorbb
Greater Faydark
Grobb
Halas
Highpass Hold
Highpass Keep
Infected Paw
Innothule Swamp
Kedge Keep
Kerra Ridge
Kithicor Forest
Lake Rathetear
Lost Temple of Cazic-Thule
Misty Thicket
Nagafen's Lair
Najena
Neriak Foreign Quarter
Neriak Commons
Nerial Third Gate
Nektulos
Northern Desert of Ro
Northern Felwithe
North Freeport
North Kaladim
North Karana
North Qeynos
Oasis of Marr
Ocean of Tears
Oggok
Paineel
Permafrost
Qeynos Catacombs
Qeynos Hills
Rivervale
Solusek's Eye
South Kaladim
South Karana
South Qeynos
Southern Desert of Ro
Southern Felwithe
Stonebrunt Mountains
Surefall Glade
The Arena
The Castle of Mistmoore
The Estate of Unrest
The Feerrott
The Hole
The Lavastorm Mountains
The Lesser Faydark
The Liberated Citadel of Runnyeye
The Nexus
The Rathe Mountains
The Ruins of Old Guk
The Steamfont Mountains
The Temple of Frozen Shadow
The Temple of Solusek Ro
The Warrens
Toxxulia Forest
Upper Guk
West Commonlands
West Freeport
West Karana