The area is filled with supermutants inside and out. Once inside, you'll find a Novice door and Expert wall safe in the NW corner of the room.
There's a Chem station behind the counter to the SE. In the NW room, you can find the Faneuil Hall Cashier’s Key with an unlocked Manager’s terminal where you can activate the hall’s protectrons.
In the topmost floor, in the corridor, there’s an issue of Live & Love on the small table beside the couch near the door.
Green steamer trunk in the room at the end of the corridor with stairs leading to the hall’s rooftop. The rooftop has a couple of lootable containers.
Underground parking, front of Faneuil Hall
There’s a novice terminal with a protectron unit beside it. If you continue to the stairs, you’ll reach an Expert door leading to Haymarket Hall. In the second level and you’ll find an Advanced Safe under the ramp. There’s a couple of elevators leading to a broken building. If you head to the overpass, you’ll unlock Garden Terrace.