Villengard

As alluded to by Jack Harkness and the Doctor, in the 51st century Villengard was an area where there were weapons factories, making such weapons as sonic blasters. The Doctor (in an unknown incarnation) 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. (DW: The Doctor Dances)

It's possible that Villengard is related to Asgard, due to the "-gard" suffix and both (presumably) existing in the 51st century.