The Island The Island ( formerly Mount Desert Island ) is a location within Maine , and is the setting of the " Fallout 4 " add - on " Far Harbor " . Background . Before the Great War , the Island was a famous holiday location , and after the war , there were small settlements all over the island . But a radioactive fog drove the locals away , and in 2287 , Far Harbor and Acadia are the only habitable settlements on the island for humans . Dependent on player actions , other settlements such as Dalton farm , National Park Visitor ' s Center , and Echo Lake Lumber can be established . The cult of the Children of Atom has also established a stronghold on the island , based within a pre - War submarine base , called The Nucleus . These religious fanatics worship the Fog and at the time of the Sole Survivor arriving on the island are at increasing tension with the inhabitants of the docks , with Acadia decidedly neutral . Layout . The Island can be reached from the Commonwealth mainland via a boat that is in the north east . In an area that is off the edge of the map found in the Pip - Boy is a house . Agree to help the couple inside , and they will let you use their boat to visit Far Harbor . The island itself is quite large and features over forty - five marked locations . The climate is cold and wet , dark and dreary , accented by rolling pockets of radioactive fog and frequent radioactive thunderstorms amongst rugged terrain and menacing woods . These rad - storms are especially frequent on the southern end of the Island . The Sole Survivor arrives in the island ' s last remaining real human settlement , Far Harbor , which is located on the far eastern coast of the island . It is also home to a group of escaped synth refugees based in a pre - War observatory on a mountaintop , called Acadia , towards the center of the island . Another major faction on the island is the religious cult of the Children of Atom . Their headquarters is a pre - War nuclear submarine base called The Nucleus , which is southwest of Acadia , off an inlet into the central part of the island . The island also features a few pre - War factories , a pre - War mill called Echo Lake Lumber , two hotels , some National Park campgrounds and buildings , a drive - in movie - theater called Eden Meadows Cinemas , Beaver Creek Lanes bowling alley , an Oceanarium , a Ruined church , Waves Crest Orphanage , and a variety of dilapidated pre - War houses , farms , and structures , many of which are now inhabited by gangs of trappers or super mutants , in addition to feral ghouls and various irradiated creatures . A semi - completed Vault - Tec vault , Vault 118 is located beneath / within the Cliff ' s Edge Hotel , just north of Acadia and can be accessed as part of the Brain Dead quest . There is also Brooke ' s Head Lighthouse on the southern coast of the island , which features prominently on the picture promoting the Far Harbor DLC . And towards the center of the island is the wreckage of Horizon Flight 1207 , presumed to have crashed there during the War . There are many ruined watercraft and small islands dotting the coastline of the main island . Some of these are inhabited by creatures , trappers , or other factions , while others are uninhabited . Instead of Nuka - Cola , the residents of the island even before the War preferred their own locally - produced soda brand known as Vim ! , which was native to New England and can still be purchased in Far Harbor and found throughout the island . There remains a Vim ! Pop factory on the southern part of the island where the beverage was produced prior to the War , now inhabited by super mutants . Environment . The Island ' s hostile environment can be attributed to the radioactive fog that blankets nearly the entire landmass that recedes and expands within the years . These constant doses of radiation are enough to drive a person mad if they linger in the affected area for too long , as seen with the trappers that reside within said affected area . That being said , the Island is seemingly a lot healthier than the Commonwealth , as there ' s a richer amount of diversity in terms of flora and fauna . Appearances . The Island appears only in the " Fallout 4 " add - on " Far Harbor " . Behind the scenes . Many of the roads shown on the map of the Island correspond to the carriage road on the real Mount Desert Island built by Rockefeller when he owned the island .