well you get a poke Flute and go to the snolax wake it up and go throe the tunnel and there you are
take it to pewter museum
Pewter mueseum :D
Pewter City
go to the museum in pewter city
At the top of pewter city in the kanto region
talk to the man on the platform in pewter city
Its in Kanto to the right of Pewter city.
go down at pewter city
to pewter city
You can fly there or go west.
After you get the silver wing from the old man in pewter city
It is in the very North western part of the Kanto region.