Jamaica Plains Town Hall Basement

Tip: This is a good place to farm Steel, crystals, and Fiber Optics by disabling the numerous laser tripwires and re-enabling them again after pressing a security button.

In the town hall, there's a set of stairs leading to the Advanced locked basement door. Once inside, be careful of the gas leak. Head to the next room then to the only unlocked door to the right. You'll see a corridor filled with laser tripmines. The Janitor's ID card on top of the card reader won't be accepted so it's either you manually disarm the tripmines (remember to order your companion or Dogmeat to stay in their position to avoid accidentally triggering the turrets) to collect a huge amount of Steel, Crystal and fiber options by disarming the laser tripmines. After reaching the end of the door, there’s a red button. Upon pressing it again, the laser tripmines will reactivate, allowing you to collect an infinite number of these specific components, as much as you and your companion can carry.

Push the button to open the security door. If you go through the broken wall, it will Lead you to the archives room with an Expert Safe and the Archives Key on the table beside the door. Back in the security door, if you have the Mayor's Password, you can use it in the main terminal in the center. There are two Expert terminals on both sides of the rooms that can be used to activate the protectrons.

Once the security door has opened, activate the button to open the treasure room. You can take the two holotapes on the table. These are the “treasures”.