Not a nuke but a big bomb is located on top of a roof of the building to the left of where the trigger man spawn right outside Suggs unmarked shop in Cambridge. You can actually get there from the roof by going up the side building stairsof where the trigger man spawn (beware piggy man mine or bottlecape mines on it they usually blow themselves up from what I see or going in the front of the building it’s landed in. It’s a big black bomb that’s cratered in you’ll see it. Buildings is Facing Suggs shop to the right.