The air around Acadia is fresh and free of fog. The observatory is situated at the top of a small mountain.
When entering through the front door there is a corridor with some stairs leading down on the right, Faraday's office/laboratory on the right past the stairs, and then the corridor leads directly into what was formerly the telescope room/planetarium of the observatory. DiMA can be found in this main room, often with Chase and Faraday. This circular room is lined with servers along the walls and has some stairs leading up to a mezzanine. There is also a door (locked initially) which leads downstairs.
Downstairs are living quarters with several NPCs and un-named synth refugees, including Dejen and Cog, both of whom are vendors.
Continuing downstairs to the next floor is Kasumi Nakano, who has fled to Acadia from the Commonwealth, believing that she is actually a synth. There are some terminals and storage rooms located down on this floor.