Quark's moon

Quark's moon was, originally, a unspecificed moon sought for purchase by Quark, as a means of defining his own success, which he measured against his cousin Gaila, who owned his own moon. (DS9: "Civil Defense", et al.)

When Quark began working with Gaila, working for Hagath as an arms dealer, Gaila assured him that by taking the job, "[i]n a year, you'll have your own moon," much to Quark's content. (DS9: "Business as Usual")

In an alternate timeline, after the Federation relinquished control of Deep Space 9 to the Klingon Empire, Quark was finally able to purchase such a moon. His brother Rom maintained the facilities on the moon, keeping it from "falling out of orbit". (DS9: "The Visitor")