Vaults of Forbidden Knowledge hold some of the best loot in Hell Is Us, and the one in Vyssa Hills isn’t an exception. As you know, there are a few things you need to do before opening one of them, mainly recruiting an NPC and gathering a lot of research items around the map. But if you’re keeping up with your research and exploring all areas in Hell Is Us, opening the Vault in Vyssa Hills will be a breeze. The real challenge, however, is locating it, but fortunately, it is easier than you think.
Locating and Opening the Vault of Forbidden Knowledge in Vyssa Hills
The Vault of Forbidden Knowledge in Vyssa Hills is the second one you’ll be able to open in Hell Is Us, mainly because its code is tied to your research level. If you haven’t, remember to give all research items to Tania inside the APC. Once you fill up the research bar for the second time, you’ll get the following code, as well as the location for the Vault.

This will lead you to Vyssa Hills, more specifically, to the vicinity of the waterfall.
In truth, this is a bit broad and might confuse a few players, but finding the vault is quite easy, especially if you know where the waterfall is, which you should, as you visited this place during the main quest.
From the start of the zone, where you parked the APC for the first time, follow the road toward the tree and turn left to see the waterfall. Take a right to climb the hill behind the waterfall and then drop down in the spot we’ve marked below:

Once you land on that spot, turn left and jump down, and then enter the cave behind the waterfall, which will lead you to the Vault of Forbidden Knowledge.

Once inside, access your research menu inside your datapad, and look for the code, which should look like the image below.

Once you input the code correctly, the Vault will open, letting you grab all the loot. Here’s what you’ll find:
- Glyph – Rapture – Enhanced (Ecstasy)
- Letter – A Spy’s Insight (Miscellaneous Item)
- Pendant of Ecstasy – Battle Bliss (Defensive Gear)
- Glyph – Animosity – Enhanced (Rage)
- Parchment – Anticipation (Miscellaneous Item)
- The Unbound Delusion (Passive Relic)
- Glyph – Void – Enhanced (Grief)
- Painting – Lady Marguerith (Miscellaneous Item)
It is important to note that while these Glyphs share the name with others you might have collected already, their Enhanced versions are more powerful, and you should equip them as soon as possible. Beyond those, the new Passive Relic is great, as it increases your Lymbic Energy at the cost of reducing the damage. A bit of a trade-off, but it is worth it, especially if you’re going for a Lymbic-focused build.