<Locations in Commonwealth> suggested by Darkflip

Mole rat den
thicket excavations
bedford station
dark hollow pond
lake quinnapowit
coastal cottage
makra fishpacking
salem
crater house
nautical radio source
old gullet sinkhole
malden drainage

mirelurk mausoleum
mass fusion disposal
sunken boat
forest grove marsh
weston water plant
makeshift camp
walden pond
poseidon reservoir
beantown brewery

vitale pumphouse
nordhagen beach
libertalia
nahant warf
oceanological society
revere beach station
yangtze
medical center metro

crashed ufo
chestnut hillock reservoir
mass pike tunnel
copley station
uss riptide
flooded boathouse
plumbers secret
public works maintenance area
irish pride shipyards

neponset park
submerged house
fms northern star
poseidon energy
light house
murkwater construction
swamp treehouse
edge of glowing sea

red rocket cave
decrepit factory
sentinel site