if its pearl go through mt cornet ,au revoir
If you keep going through Mt Coronet you'll eventually reach Spear Pillar, where you catch Dialga, Palkia and Arceus. You can't fly from Spear Pillar, though.
at the top of mt coronet(arch=spear pillar)
spear pillar
you have to go through Mount coronet the route 208 way hope this helps
Spear Pillar is exactly where it was in Diamond and Pearl; Mt. Coronet.
in spear pillar in the middle of mt. coronet
up at spear pillar which is scrambled through a maze in mt coronet after an event (no hacks,AR or toys r us) that will happen after a while.
the top of mt cornet is spear pillar
Dialga is in Spear Pillar and Spear Pillar is located deep in Mt. Coronet.
You go to mt. coronet from harthome city.
in the very middle
in spear pillar after the snowpoint gym challenge (spear pillar is in mt coronet)