The Townlong Steppes is located in the northwestern part of Pandaria and the zone borders both the Kun-lai Summit and the Valley of the Fourwinds. Once home to the Yaungol, it is the ancestral home of the Mantid, the race that forced the Mogu to build the Pandaren Wall to protect Pandaria. As the Mantid have attacked 100 years too early, the Wall is under attack once more.
The zone contains two dungeons, the Gate of the Setting Sun and the Siege of Niuzao Temple. Blizzard describes it thus (even if they get the name of their zone wrong):
Separated from the rest of Pandaria by the Pandaren Wall, the rampaging mantid people of the Townlong Wastes devour everything in their path in order to build their own crystalline empire of ruthless warriors and scheming feudal lords. The pandaren are left reeling when the mantid’s thousand-year cycle of aggression kicks off a hundred years too early and their greatest warriors burst through the Pandaren Wall. The beleaguered pandaren must now face the worst swarm in recorded history while trying to isolate the cause of the mantid’s erratic behavior.