mirage tower only appears in pokemon emerald.
Armaldo and Cradilly.
In the desert and in mirage tower.
they are at the top of mirage tower the tower in the desert north of mauville city
go into the desert,and find the mirage tower
mirage tower or desert underpass
In the Mirage Tower nefore you get the Fossil
In mirage tower ( at desert near route 111)
Mirage tower will appear after talking to the fossil maniac he can be found just west from fallarbor town after talking to him go to the desert the tower will be there, you need the mach bike to go through the tower.
Ditto is found in mirage tower you can make the tower appear after talking to the fossil maniac.
Mirage Tower is in the desert around the enterance near Mauville. It only appears every once in awhile. I'm not sure how often though.
Mirage tower and underground tunnel in the fossil maniacs house.