Fallout 4’s map (Commonwealth) is pretty damn big, Which can possibly take up to a couple of months to fully explore. So it shouldn’t come as a surprise to anyone that there’s a ton of hidden areas you probably missed out on.
Here’s a few locations you probably missed out on. You just need to make sure you watch out for those damn Deathclaws.
The Parking Garage Dungeon
This building is located next to the Milton General Hospital. The parking garage dungeon or maze has a labyrinthine structure with locked door puzzles, frightening mannequins and a lot of traps. You should make sure you saved the game before entering the garage. If you have played Fallout 3 the structure will remind you of the Dunwich Building.
The Rocket Shed
The little shed built on a cliff is located to the northeastern side of Relay Tower 0BB-915. The interesting thing about this shed are the little ramps facing towards the wasteland. You can place the already present tanks in the shed on those ramps and shoot them. It’s fun.
The Orca Wreckage
You can find the wreckage of the Orca when you head towards the bay north of the Salem Museum of Witchcraft. You’ll spot a half sunken ship and once you climb on the deck you’ll find a huge porpoise and a corpse of the Quint of the ship. You can also dive in the water to find a diver’s cage.
Old Gullet Sinkhole
Old Gullet Sinkhole is a location in Fallout 4, as the name suggests is a home to a monster lurking an abyss loaded with garbage. You can complete the quest Fallen Hero and retrieve Joe Savoldi’s grandpa’s old hat. To reach the Old Gullet Sinkhole, you’ll need to jump down the crater following the rushing water.
The entrance of the Old Gullet Sinkhole and then you need to slide into the cave. Along the way you’ll have to face and defeat a Deathclaw, some ghouls and some other pests, and it’s worth it as there’s lot of loot inside.
You’ll need to head towards the southwest of the Massachussets State House and the heading further west of the gazebo at Swan’s Pond to find the bar. The word Prost means “cheers” in German and the bar consists of a mailman and a patron on its further end, but at this bar, no one knows your name.
Yangtze is a Chinese submarine in the middle of the ocean, as it is a part of a side quest. You must take the quest named “Here There Be Monsters” by speaking to a young boy named Donny Kowalski. The boy can be found standing at the dock looking at the sea behind the Shamrock Taphouse.
The map marker will be available once you take the quest from him. You’ll then get the permission to enter the submarine and continue the quest which involves an interesting character named Captain Zao.
Back Alley Bowling
You can find the Back Bowling Alley when you go to the General Atomics Galleria. Back Alley Bowling has 39 bowling balls, 37 bowling pins and a few bots named Tenpin, Split, Strike, and Kingpin, which can become hostile if you go past the counter. You can also toss bowling balls at the bots or load the balls in the junk jet for more fun.