Tunnels

Tunnels or QASmoke is a test cell in Fallout 4 that can only be accessed via the console command.

Layout
It is named "Tunnels" on the local map and contains the majority of items in the game, including some of the unused content, such as the Vault 101 jumpsuit.

This room is made up of various building pieces with an open area that contains every crafting station, two rows of power armor, and containers for each of the categories of items. There is an assorted amount of ammo, and most of the aid items hold around 200 of each individual item. It has every individual copy of each of the magazines, pieces of clothing, weapons, and holotapes.

Several quest items are available in the containers, and if they are collected, their associated quests will be initiated if they have not already been completed.

There are additional containers available for each add-on that provides additional items that are installed. In addition, if Nuka-World is installed, the Nuka T-51 and Quantum X-01 power armors will be available.

Appearances
Tunnels appear only in the game files of Fallout 4.

Behind the scenes
Identically-named test cells exist in Skyrim.