Talador is a new zone introduced with Warlords of Draenor located in the southern central part of the main Draenor continent. It is a draenei zone that would have become Terokkar Forest in the original timeline. It will have an autumn theme, similar to the Vale of Eternal Blossoms before it's destruction.
Shattrath City is found here, though is much larger in scope than what is known today, spreading deep into the zone and resting on the edge of the Zangar Sea. Auchindounn, pre-shattering, is also here as well.
Blizzard official description
Talador is the heart of Draenor. It rests at the crossroads of the continent, divided by rivers that flow from the Sea of Zangar and enable marine trade and movement from east to west. At the center of Talador shines the glorious cathedral city of Shattrath: a museum metropolis, an architectural marvel, a preserved recreation of ancient draenei culture—entirely occupied by the Iron Horde.