This guide lists every vault fragment location in Borderlands 4 across Kairos, explaining where each region’s vault is situated so that players can craft keys and open primordial vaults for high-tier loot. It saves time by grouping fragments by region and giving short traversal hints to reach each fragment without endless searching.
Borderlands 4 places three vaults across the map, and each vault needs three fragments to assemble its key. The three regions with fragments are Fadefields, Carcadia Burn, and Terminus Range. Collecting all nine fragments yields three keys that open the Arch vaults hidden in those biomes. The locations below list each fragment and the vault site for quick reference.
Fadefields
Fadefields sits on the southern stretch of Kairos and contains three fragments around the Coastal Bonescape, The Howl, and Idolator’s Noose. The first fragment is on the small beach near the Stillshore POI, sitting on a crate at the pier. The second sits north of Launchpad on a ledge in the craggy hill near the farm road. The third is under a loose grate at Rosemary’s Reserve in Idolator’s Noose and requires the grapple to access.
The Fadefields vault, the Arch of Inceptus, waits on a hill in the Dissected Plateau southeast of Idolator’s Noose. Climb from the Stubs POI, look for the triangular plinth, and insert the finished key to enter. The vault interior holds the usual random high-tier rewards. These vaults are worth the detour if players are hunting for better gear.
Carcadia Burn
Carcadia Burn is the northwestern area and hides fragments in Lopside, Tonnage Peel, and the Ruined Sumplands. The Lopside fragment sits atop a structure’s banquet table near Yawning Yard or just south of the Makeshift Chalet Safehouse if approaching from the opposite direction. The Tonnage Peel fragment is inside the Wreck of the Last Great Hope cavern reached by grappling through a manhole. The Ruined Sumplands fragment is on the waterfront north of Hull’s Basket, down by the beach.
The Carcadia Burn vault, the Arch of Radix, stands near the Grindstone of the Worthy in the centre of the biome. Approach from the Ruined Sumplands and look for the open area to the right after the bridge. Slip the key into the plinth and move inside to claim gear. These fragments are straightforward once the general locations are known.
Terminus Range
Terminus Range is a bright mountainous area on the east side with fragments at Cuspid Climb, Windspear, and the Low Leys. The Cuspid Climb fragment requires some climbing and gliding to reach a small cave past the Goredello. The Windspear fragment sits on a chest inside the Vestal Garrison past the large door with a grapple point. The Low Leys fragment is glued to a stone obelisk near a frozen landslide south of The Pit point of interest.
The Terminus Range vault, the Arch of Origo, is hidden in the Low Leys near a spiky rock that points to a cave entrance. From the Heritage Opus safehouse in Cuspid Climb, head north across the border bridge and look for the spiky rock by the road. Jump the gap and enter the cave to open the vault with the crafted key. These vaults are reliable sources for rare drops and worth a revisit after leveling or respecing.
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