Hellfire Peninsula

Zangarmarsh

Terrokar Forest

Nagrand

Blade’s Edge Mountains

Netherstorm

Shadowmoon Valley

Shattrath
Shattrath is the only really major city in Outland and provides most of the facilities you would expect from a city of that magnitude. It also looks pretty cool.
It lacks a few important major city characteristics which, based on Blizzard’s comments, may never be added. Class trainers are one, an auction house is another. You will find neither of those anywhere in Outland. The reason for this? They don’t want the entirety of level 60+ horde and alliance players making Shattrath their permanent home, for lag reasons.
Shattrath lies in Terrokar Forest, which connects to Nagrand, Zangar Marsh and Hellfire Peninsula. In addition, Aldor rise is directly connected to Nagrand. Shattrath is home to the Aldor and Scryers reputations. See the reputations chapter for more information.