The fallen skybridge is a tangle of pathways allowing the passage between many skyscrapers. It allows ideal access to the Hub 360 skyscraper, one of the tallest buildings in Boston. It is located at the top of the freeway. Stair access is at the intersection of four alleyways, south-southeast of Goodneighbor, across the street from the Custom House Tower apartment building with the yellow "Now Leasing" sign on it.
On the under layer of the skybridge, there is a tank. It is also accessible via the elevated freeway. First, the Sole Survivor must traverse an undamaged onramp to the lower freeway in Quincy and proceed towards the city center. Along the freeway, there is a collapsed section which leads to the upper part of the freeway. The skybridge is found at the far end where the freeway breaks.
It is possible to jump from the skybridge directly into Goodneighbor. There will be a loading screen about halfway down the fall, but when arriving in Goodneighbor, the player character will be in the same position as they would be when coming from the normal entrance and take no fall damage.
The fallen skybridge appears only in Fallout 4.