Westland: Secrets

Free perk: the three bottles

Three grey perk bottles, held by zombie hands, are hidden on Westland. The player breaks each one with the knife; a sound confirms it.

At the spawn: on the right of the players when they appear.
In the Buried part, at the large tree before the mines: behind its trunk, going straight on from Vulture-Aid.
In the mines: down the long tunnel, by a purple crystal.
Once the third is broken, a ghost appears and offers a perk bottle. The perk is random, and it adds a perk slot.

A perk bottle breaking in a flash of light behind the trunk of the large tree of the Buried part, Westland, Call of Duty Black Ops III Zombies

The bottle of the tree

Hidden behind the trunk, broken with the knife.

A green hooded ghost in the mines, beside a large purple crystal, Westland, Call of Duty Black Ops III Zombies

The ghost of the bottles

The hooded ghost that comes once the third bottle is broken, here in the mines by a purple crystal.

Free perk: the fountain

Throw a grenade into the fountain of the Buried part.
Find the coin. Flapix gives three possible spots: on the counter of the General Store by the cash register, upstairs on crates, or on crates in the bank, the room across from the fountain. A player of the Workshop forum also found it on the counter of the room of the shield.
Interact with the fountain to make a wish. A ghost brings a random perk, with one more perk slot.

The round fountain of the Buried part with its glowing blue statue, Westland, Call of Duty Black Ops III Zombies

The fountain

A round basin with a statue, in the Buried part.

The ghost of the fountain

It appears by the fountain with the perk bottle once the wish is made.

The free M1 Garand

At the tree of the Buried part, before the mines, interact with the badge. It becomes a soul box: kill 20 to 25 zombies nearby, according to Flapix.
The badge falls on a crate. Pick it up.
Put it in the skeleton hand that comes out of a grave in front of the saloon. It gives a key in return.
Open the cabinet with the key, downstairs next to the staircase of the building on the left, and take the M1 Garand.

The songs

Two songs are hidden on the map, according to Flapix.

Samantha's music box, open on a wooden crate in the room of Double Tap, Westland, Call of Duty Black Ops III Zombies

Three toys

Samantha’s music box in the room of Double Tap, by the teleporter; a monkey doll behind Stamin-Up; a bunny in the room of the Pack-a-Punch, in the Dark Aether.

Three teddy bears

In the room to the left of Quick Revive under the spawn, in a mine cart in the mines, and in the Buried part near the meteor, not far from Vulture-Aid. Flapix says that the song is chosen at random among the main songs of older maps.

The ghost train

In the mines, go to the opposite side of the mine cart with the skull and walk toward it while looking at it. A ghost train rushes at the player. It does no damage.

The bank

The bank of the Buried part keeps the points of the players: they can deposit and withdraw them, and give points to a teammate. The update of October 31, 2022 fixed bugs of the bank.

The Paralyzer

Pankake101 shows a side quest for a weapon called the Paralyzer: a button to hold in a room beyond Stamin-Up, then the terminal next to the IDM. Pankake101 never got it to work, and no other guide describes it.