Tulgana IV is a planet hosting a Federation embassy and a busy job fair, visited by Boimler and Mariner in two missions.
Tulgana IV is a world home to a Federation embassy and a bustling, sometimes rough civilian population. In Envoys, Boimler and Mariner fly the Klingon general K'orin there, and after he steals their shuttle they search the planet for him, meeting a series of locals along the way.
The planet returns in Reflections, when Ransom assigns Boimler and Mariner to staff the Starfleet recruitment booth at a job fair on Tulgana IV. There they are mocked by attendees including the archaeologist Petra Aberdeen, until Boimler's rampage draws enough attention to meet their sign-up quota.