Jamaica Plains

This is a large potential settlement that's completely overrun by ghouls. The actual settlement area covers a small area between the chapel and town hall. When you're clearing it, make sure to keep aware of your surroundings since some ghouls will just wake up and attack you in hordes. Your main point of interest is the town's city hall. Head to the second floor and kill the ghouls inside the barricaded office. (You may encounter a legendary ghoul here) Inside the office is a named corpse (Sal). You can get the Mayor's Password from her, her holotape and some good loot.

The town hall's basement is where the town's "treasures" are located, which are also the object of interest of the doomed treasure hunters you'll find in the town. The Mayor's ID and Password can be looted from these corpses and can be used to fully access and explore the area.

After clearing the town, you'll need to find the workshop SW of the town, inside a broken building with a Power armor station.

The chapel near the settlement area is locked but can be accessed from the red house beside it. There's an assault rifle trap in the upper level and the body of Luke Silverhand near the door and the cooking station. You can get the Mayor's ID from his body, which can be used to disable the security system in the town hall basement.

In one of the houses to the NE, you'll find the bodies of Tanya and Ken Standish with an ammo box nearby. Another named corpse, Carl Everett can be found in the road crossing. Loot his body as well.