How do I get to matu keep?

What quests/mission do I have to complete?

the counts daughter if im not mistaken. starting from zin ku corridor, through the sunjiang disctirct explo, a bit through pongmei and you'll be there.

There isn't a mission that takes you there directly. But yes following the counts daughter quest, once you get out of the city and into Pongmei Valley near the place where all the paths cross, just run back towards the city and you'll see the entrace for Maatu Keep.

You can run there from Senjis Corner... Which is fairly easy as i did it on my Ranger because i desperately wanted a White Tiger.

But if you want to get there via the story i believe you get there by doing the primary quest given to you in Zin Ku Corridor. Which is the outpost after Tahnnakai Temple. You don't go to it directly but you pass it on the way to quest completetion if i remember. As you get into Pongmei Valley just keep going east until you pass the ruins and come to a field with Tigers an what not. Head north and not south and tada you're there.

Running from Senjis: http://img505.imageshack.us/img505/9430/maatu25iv.png
Quest from Zin Ku: http://img483.imageshack.us/img483/3416/maatu0jj.png

Routes aren't drawn to perfection... Probably nowhere near it but it gives you a rough of idea where your going.

Yes there is. Completing the Sunjiang District mission will drop you in Maatu Keep. However, as stated above, most people enter Maatu Keep as they pass in front of it during the Convocation quest on the way to Arborstone.