It is located in Veilstone City.
Veilstone City
Veilstone City
in vielstone city (were the fighting type gym is)
You can find it at the Galactic Warehouse in Veilstone City.
The Storage Key opens the Galactic Warehouse in Veilstone City. It is dropped by a Galactic Grunt in Veilstone City after you beat Jupiter at lake Acuity.
Galactic Werehouse is in Veilstone City (west/left side) right inside coming from Solaceon Town
Fly to Veilstone City and go into the Galactic Warehouse and get to the Pokemon of the lakes and rescue them.
There is no GBA version only DS and on DS it is in the Galactic warehouse near the entrance to veilstone city.
In the galactic warehouse in vailstone city
Go to Veilstone City and go into the Galactic Warehouse
it is not really secret but there is the building in the north part of eterna city and a building in north veilstone city
it is in veilstone city