Find the Treasures of Jamaica Plain

Find the treasures of Jamaica Plain is a miscellaneous quest in Fallout 4.

Detailed walkthrough
Find the Treasures of Jamaica Plain is a miscellaneous quest triggered by finding Hadrian's body, which appears randomly throughout The Commonwealth, and listening to Hadrian's invitation which is located in his inventory. It can also be triggered by finding and reading a Jamaica Plain flyer, found in various places throughout The Commonwealth. Alternatively, one can simply locate Jamaica Plain and enter the town hall's basement without having actually triggered the quest.

Upon discovering Jamaica Plain, the player will need to locate the Jamaica Plain Town Hall basement. The town hall is found in the Southern portion of the town and easily visible as it's one of the biggest and most distinct buildings in the area. The basement is to the left of the main entrance and down a set of stairs.

Jamaica Plain itself is swarming with Feral ghouls. Its highly advised to come here ready to face several of them at once and to not go ill-prepared for such an encounter. Clearing the town of Feral ghouls is not a prerequisite of entering the basement, however.

In the basement itself, the player will quickly make their way to a small hall filled with laser trip wires. Activating one of them will cause several turrets located near the end of the hall to begin firing in their defense of the "treasures" located within. These trip wires can be disarmed one by one, giving the player steel and fiber optics for each one disarmed. They can also be disarmed by using the Mayor's ID card at a computer panel located in front of the hall. The Mayor's ID card itself is found on a dead body located inside the church across the town from the town hall. To obtain it, one would need to access the building through the roof as the entrance is chained from the inside.

Once through the door guarded by the trip wires, following through the remainder of the basement and going through a few more doors will lead to the "treasure" of Jamaica Plain itself, containing the 2076 World Series baseball bat and many unique pre-war items not found elsewhere in the game. There are also some holotapes on the table immediately within the room, such as the Treasures inventory holotape, which lists items that are found in the vault and the reasons for it existing. However, given the passage of time most of the artifacts suffered heavy degradation.