
Cardassian Union insignia image.
The Diplomatic Service building is a location in Cardassia City where the Cardassian Union's diplomatic body is based. It is near the Hall of Records.
In the 2350s, Elim Garak travelled to the Diplomatic Service building (as Alardig Ra'orn) to begin his undercover assignment to Tohvun III. (DS9 novel: A Stitch in Time)