
This is the map from Pokémon Mystery Dungeons Blue Rescue Team which shows all of the friend areas in the game.
I will list the place names and then put a picture of which legendary resides there after you recruit them.
Stratos Lookout (Sky)

Deep-Sea Current (Northern Sea)

Final Island (Western Isles)

Legendary Island (Northern Isles)



Cryptic Cave (Cave Area)

Enclosed Island (South-West Isles)

Healing Forest (Western Forest)

Sacred Field (Plains)



Rainbow Peak (Mountain Range)

Southern Island (Southern Isles)


Seafloor Cave (Southern Sea)

Volcanic Pit (Volcano)

Ancient Relic (Relics)



Ermm I think thats them all :)
Hope I helped
Source