Zog (planet)

Zog was a planet which had a city named Zagizalgul. Within the city was a bar where Jack Harkness visited. The Doctor, before his tenth regeneration, came to the bar as well to introduce Jack to Alonso Frame. The two men chatted as the Doctor left. (DW: The End of Time) It is also implied that the Doctor previously visited the planet with Donna Noble. (DW:The Unicorn And The Wasp)

Trivia

 * When Jack was at the bar, the following aliens were present; an Adipose, a Raxacoricofallapatorian, Judoon, Hath, Sycorax and Graske, as well as additional unknown species.