KF2 Netherhold: Collectible Skulls and Hidden Rooms

Netherhold is a Halloween-themed Killing Floor 2 map full of secret rooms. Its demon-skull collectibles (the Forgotten Knowledge set) unlock achievements once destroyed, and several of them are hidden behind breakable walls. This guide, written during the map's preview and later updated, walks through every skull room by room and also explains how to open each hidden room. Related: overview of KF2 collectible maps.

The route is grouped by area, with the number of skulls in parentheses. Hidden rooms are separate sections because some also count toward the seasonal objectives.

Netherhold collectible skull (Forgotten Knowledge)

Gear room (1)

The skull is at the bottom of the bags.

Gear room (1)

Blacksmith room (1)

The skull is in a bucket.

Blacksmith room (1)

Stairs near the dining room (2)

One is in the display case above the stairs leading down to the outside (break the glass). The other is above a shield on the stairs to the basement.

Stairs near the dining room (2) - 1/2

Stairs near the dining room (2) - 2/2

Church (1)

The skull sits in the hands of the big statue.

Church (1)

Hidden room: Altar (3)

This room is right next to the church behind barely open doors; entering it, together with the dining room, is part of the seasonal objective. Pull the lever on the pillar between the doors. You can also break the glass in the doors: the right one hides a skull. A second skull is under the altar and a third is on a beam above it.

Hidden room: Altar (3) - 1/4

Hidden room: Altar (3) - 2/4

Hidden room: Altar (3) - 3/4

Hidden room: Altar (3) - 4/4

Front of the church (1)

A trader stands here; the skull is right next to it.

Front of the church (1)

Hidden room: Nether Heart (1)

Still in front of the church, look for a glowing purple wall and destroy it. This room is also part of the seasonal objectives. The skull hangs on one of the branches on the left.

Hidden room: Nether Heart (1) - 1/3

Hidden room: Nether Heart (1) - 2/3

Hidden room: Nether Heart (1) - 3/3

Hallway with the hand (1)

The skull is right next to the hand.

Hallway with the hand (1)

Hidden room: Office (1)

To the right of the hand is a strange wall; destroy it to reach the office. A second entrance is in the room with the stairs near the dining room. Look up for a grated hole with a direct view of the pitchfork devil, which holds the skull in its hand.

Hidden room: Office (1) - 1/3

Hidden room: Office (1) - 2/3

Hidden room: Office (1) - 3/3

Glowing rock (1)

The skull is on top of the glowing rock.

Glowing rock (1)

Basement (3)

One is in the blocked hallway near an opening to the outside. One is in the cage right in front of the secret dining room entrance. One is in a cage in the hallway with the eye at the end.

Basement (3) - 1/3

Basement (3) - 2/3

Basement (3) - 3/3

Hidden room: Dining room (3)

Look at the floor in front of the caged skull: there is a circle with runes. Break the glass to fall in and be teleported into the dining room, which opens its doors (also a seasonal objective). One skull is on a ceiling beam; another is hidden in a plant just left of the breakable wall; the third is inside the cupboard on the right after teleporting (break its glass first).

Hidden room: Dining room (3) - 1/4

Hidden room: Dining room (3) - 2/4

Hidden room: Dining room (3) - 3/4

Hidden room: Dining room (3) - 4/4

Hidden room: Laboratory (1)

The middle wall of the dining room glows purple; destroy it. The skull is in the right corner behind the rolling cart. Jump to see it.

Hidden room: Laboratory (1) - 1/2

Hidden room: Laboratory (1) - 2/2

Wine cellar (1)

Under the floor, on a coffin.

Wine cellar (1)

Outside (3)

One is in the toilets. One is in the background in front of the trader. One is on the roof on the left side.

Outside (3) - 1/4

Outside (3) - 2/4

Outside (3) - 3/4

Outside (3) - 4/4

Hidden room (three breakable walls)

Three walls can be destroyed to reach it: one at a building entrance (with a skull in the blocked hallway to the right), one at a dead end in the basement, and one next to the stairs.

Hidden room (three breakable walls) - 1/4

Hidden room (three breakable walls) - 2/4

Hidden room (three breakable walls) - 3/4

Hidden room (three breakable walls) - 4/4

Hidden room: Waiting room (1)

Break the closet with boxes near the pillar stairs. A skull sits on one of the cabinets.

Hidden room: Waiting room (1) - 1/2

Hidden room: Waiting room (1) - 2/2