Emerald Sky Pillar
A ruined spire far out past the southern routes, the roost of Rayquaza. Wallace leads you up to wake the dragon and stop the Kyogre and Groudon rampage. Return with the Mach Bike to catch it.
Sky Pillar is in Hoenn, with Route 131 to the south. In the story it comes after Ancient Tomb and before Victory Road.
SKY PILLAR MAP
Wallace leads you to the Sky Pillar mid-story to wake Rayquaza, long before most games would let you near it. Only the return climb is a Mach Bike sprint over brittle floor tiles that give out the moment your speed drops, sending you down a level.
Pokemon Encounters
The upper floors of the Sky Pillar field Banette, Claydol, and a 6% Altaria, a respectable spread for a tower this late. Rayquaza waits at the very top at level 70, the one-time catch the whole climb is built around.
Rayquaza
Sky Pillar Guide
Right in the middle of the story. The moment Groudon and Kyogre tear into Sootopolis, you're packed off to the top of the Sky Pillar to wake Rayquaza and send it to break up the fight. Catching it is part of the main game here, not a victory-lap errand for after the credits.
Not yet. The first trip only wakes it for the story scene, when it flies off to calm the titans. You return to the Sky Pillar afterward for the real catch, finding Rayquaza at level 70. Only that return climb is a Mach Bike sprint over the collapsing floors.

