You will come across a number of barred doors that will arrest your progress in Hollow Knight: Silksong. The keys that unlock these doors are scattered across Pharloom, some in the possession of merchants or enemies.
This Hollow Knight: Silksong guide is a complete listing of all key items and Simple Keys, and their locations.
Architect’s Key
Rotary key of the Architects. Opens their Chapel in the Underworks.
Unlock the Architect in the Underworks with this key acquired from the Twelfth Architect himself. This is where you will find the Architect’s Crest.
Bellhome Key
Key to a restored bell above Bellhart.
Complete the Bellhart donation related wishes and speak with Pavo to exhaustion, in order to receive the key to Hornet’s new home situated in Bellhart itself.
Diving Bell Key
Small worker’s key. Unlocks the door to the diving bell in Deep Docks.
Required to access the diving bell in the Deep Docks, which in turn opens up the path to reach The Abyss. After unlocking Act 3, return to the last bench and locate Ballow in his new spot above the Bell.
Simple Key #1
Rusted key of common design. Can be used to open a range of simple locks.
Degraded by time, it will break after a single use.
The earliest Simple Key can be simply purchased from Pebb in Bone Bottom for a steep 500 Rosaries.
Simple Key #2
Another easily purchasable key can be had from Jubilana, as soon as you unlock her store by completing “The Wandering Merchant” wish. This location is in Songclave within the Choral Chambers.
Simple Key #3
This key will require defeating a Roachkeeper. To reach this fight, head to the pinnacle of the tallest shaft in Sinner’s Road.
Simple Key #4
The last of the Simple Keys is located on the far right end of Sands of Karak. Having Clawline will be necessary to reach the hidden destructible wall at the apex of the tall shaft near the Pinstress.
Surgeon’s Key
Discarded key of the Whiteward. Opens the sluice beneath the operating theatre.
Access The Unravelled boss in the bottom left of Whiteward with this key that is found on a corpse located diagonally opposite in the top right of Whiteward. Requires Clawline to reach.
Key Of Indolent
Key with the mark of ‘Indolent’. Opens the way to certain cells and passages of the Slab.
One of two unique keys to be found in The Slab, the Key of Indolent is located in one of the dead end passages on the left side, about halfway down. Simply head left when you encounter Grindle on the other side of a locked door.
The Key of Indolent opens up three doors in The Slab for further exploration.
White Key
Finely crafted metal key, shaped to resemble a surgical implement.
Grants access to the Citadel’s Whiteward.
Another key from Jubilana, this key unlocks entry to the Citadel’s Whiteward. You can actually acquire it for free, if you stumble upon it in Choral Chambers on a corpse, but only before completing “The Wandering Merchant” wish.
Those are all of the unique keys and Simple Keys to be found in Hollow Knight: Silksong.
