How to get to Kod'Taz, Broken Trial Grounds
In order for you to get to Kod'Taz, Broken Trial Grounds, you'll first need to achieve level 60 or complete enough GoD Progression to be allowed access to this zone. Once you're able to access this zone you can reach it by traveling to the northwestern most portion of Natimbi which is where you will find the stone shown in the screen shot above. Click on the stone to zone in.
Getting to Natimbi is actually more annoying than getting to Kod'Taz - believe it or not. Those of you unfamiliar with How to get to Natimbi, follow the link provided to be taken to a guide explaining exactly how to get here. Alternatively, if you're playing on a TLP that's got Dragons of Norrath released you can just take the Guild Hall to Barindu then back track through Qinimi and to Natimbi too.