Villengard

Villengard was a location in the 51st century where there were factories making weapons such as sonic blasters. Jack Harkness and the Ninth Doctor spoke of them. At some point the Doctor caused the reactor to go critical, which vaporised the factories. Eventually, a banana grove grew there, which the Doctor used as a justification for his actions (along with swapping Jack's sonic blaster with a banana that was grown in said banana grove). (TV: The Doctor Dances)