Old Gullet Sinkhole

There is a green steamear trunk near the sinkhole. Be careful since a Deathclaw will ambush you. If you wade through the hole, you'll fall into a cavern with a cooking station and an issue of The Wasteland Survival Guide. The skeleton there is actually the grandpa of one NPC in Bunker Hill. Collect Grandpa Savoldi’s Hat so you can return it to him when you visit the place.

Just follow the tunnel and you'll reach basement with some ghouls. You can go upstairs to return back to the surface. You'll find yourself in a house with a chained door. In the second floor, there's a Novice safe.