Surplus Depot Z15 in 2368
A junkyard, ship graveyard or surplus depot was a disposal site for defective, damaged, outmoded, and otherwise unused equipment.
After entering the Delta Triangle in 2269, Captain James T. Kirk of the USS Enterprise observed that what they discovered was "like a vast Sargasso Sea. A graveyard of ships from every civilization imaginable." (TAS: "The Time Trap")
The Qualor II Surplus Depot Z15 was a Federation junkyard that contained the hulks of numerous retired starships, along with at least two space stations. Among the identified vessels that were located at the depot were the Vulcan transport T'Pau, located at Section 18-Alpha-12, and the holding vessel USS Tripoli, located along the outer rim. (TNG: "Unification I", "Unification II")
When Miles O'Brien checked the remaining technological components of the SS Santa Maria on Orellius to contact the runabout he found nothing. Everything was removed and it looked like the ship went through a Ferengi junkyard. (DS9: "Paradise")
Michael Eddington compared the "modifications" Rom did to the computer systems of the holosuite with a junkyard. (DS9: "Our Man Bashir")
Occasionally an entire space station became abandoned and a junkyard in itself, such as the Cardassian space station Empok Nor. (DS9: "Empok Nor")
Vic Fontaine compared Mister Zeemo with a junkyard dog. (DS9: "Badda-Bing, Badda-Bang")
Abaddon was the owner of a Delta Quadrant junkyard known as "Abaddon's Repository of Lost Treasures." (VOY: "Alice")