It's a DLC zone. So first off you have to buy it (unless you're ESO+ member, then you get "free" access to it). Then you have to go to the main starting city (AD: Vulkel Guard, DC: Glenumbra, EP: Davon's Watch), where an Orc will approach you with a quest to send you there.
AlphaCrucis wrote: »How do you access this zone?