Explore Vault 88

Explore Vault 88 is a quest in the Fallout 4 add-on Vault-Tec Workshop.

Detailed walkthrough
To locate and activate each of the workshops in the remaining three sections of the vault, you must find their corresponding Vault-Tec control boards. The sections are comprised of the North sector, the North-East sector, and the East sector.

The Northern sectors are accessed by using the workshop to clear a massive rockfall, revealing a passage beyond with a stairwell. Down the stairs, partial construction can be seen of vault corridors. There are several mole rats here. Following the passage to the right will lead up a small tunnel to a stairwell filled with feral ghouls. The North-East control board is in a room behind the first stairwell. Heading through the hole in the wall opposite the doorway (Going further up the next set of stairs leads to a barricade that requires the workshop to clear) leads to a ledge, below which is another open chamber with the North-East workshop on the left. On the right is a passage that leads to the North workshop.

Heading downhill from the North workshop is a subway station with more ghouls residing within. The North control board is located on a cabinet in the right-hand platform room.

The eastern wall at the main chamber has two tunnels, one of which is blocked by impassable debris. The one on the right has a rockfall which can be cleared via workshop, revealing a tunnel beyond. Heading straight and going through the doorway on the right gives you a room containing three feral ghouls and the control board. Further down the tunnel will be a large chamber with a Softshell mirelurk in it. Upon entering the chamber, another mirelurk and a mirelurk hunter will emerge and attack. Once they are dead, a mirelurk queen will appear from the water at the far end of the room. With the mirelurks cleared, you will then have easy access to the East-sector workshop which connects its path up to the main workshop, also including a massive water pump that provides 100 water to the Vault.

When each workshop is up and running, the quest will complete, and you will be able to explore Vault 88 further using the workshops to clear your way.

Bugs
Completing all of Explore Vault 88 quest objectives prior to turning on the beacon will cause the quest to not complete.

Not a bug as such, but worth noting. If you're on a repeat playthrough and decide to use console commands to speed through this quest - don't! Although the quest appears to advance with commands, in reality, using the console for this quest will cause a lot of unwanted issues further down the line. Most specifically, if you don't clear the rubble, manually explore the areas and activate the three additional workshops in the correct way, you will be unable to build in any of the three extra zones.