Question

Where is the sky pillar in the emerald version?

Comments

*sigh* why do people keep voting down good questions?

Answer 1

Go east of Pacifidlog Town.
Surf untill you see a big island.
Go to that island. There's a tower enter it. You've just arrived at the sky pillar! (At the top is Rayqaza but you'll need a mach bike to arrive there...)

http://pokemon.wikia.com/wiki/Sky_Pillar
(To see how it looks)
Hope this help!

Answer 2

Go to Pacifidlog Town.
Surf east and make sure to keep close to the top of the route, or you might miss the entrance. There is a zig-zagging passage of water that can be passed if not watching carefully.
Once you find the passage, simply Surf north until you come upon the island.

Inside the tower are:
Sableye
Claydol
Altaria
Banette
Rayquaza (obviously only one)

Make sure to bring the Mach and not the Acro Bike because you will need the Mach Bike to navigate the falling tiles inside the tower.

You can find maps of the different floors of the Sky Pillar at:

http://bulbapedia.bulbagarden.net/wiki/Sky_Pillar