Door To Door

The Zskera Vaults is a new weekly "puzzle" vault we get to do in the Forbidden Reach. The Vault and it's contents change minorly in orientation each week, but the layout is the same, and consists of a large circular chamber with 4 floors. Each floor has 7-8 rooms. You'll loot [item=202196] from killing rares and looting treasures on the Forbidden Reach. Since the treasures are farmable you can technically farm as many keys in a week as you're able and notably they're also BoA so you can send keys from your alts to your main and vice versa if you need more keys.

Unlike similar concepts from the past such as Torghast, you can come and go as you please throughout the week. Your progress in the Zskera vaults will be saved, which is to say any door you opened will remain opened for the rest of the week on that toon so if you don't have many keys you can do part of the run and then come back later in the week to open more doors.

On the PTR the Zskera Vaults runs I did were for Vault Az (which had 29 doors to open) and Vault Urr (which had 30 doors) meaning that if you're doing this achievement on a single toon, it would take about 2 week to complete it, and 6 weeks total to complete the follow-up achievement Door Buster.

However both achievements are account-wide progress, so if you're in a rush to complete them you can farm 150 keys and do runs on 6 toons to speed the process up. If you're doing this, note that the initial quests to unlock the Zskera Vaults takes about 15-20 minutes of questing and as of PTR there is no skip for this intro. You also receive 6 keys for doing those quests for each toon that does them.