Where to Find Smooth Rock in Pokémon Pokopia — Onix Habitat Guide
The Smooth Rock is needed to build the Smooth Tall Grass habitat for Onix. Here's exactly where to find it in the Withered Wasteland cave.
by VGC
Smooth Rock Location
The Smooth Rock is inside a glowing Pokéball in the same cave where you rescued Onix, in the northwestern corner of the Withered Wasteland. You'll likely already have it in your inventory by the time you need it.
Head west of the Pokémon Centre, break through the rocks, enter the cave on the right by the water, head toward the green building and take another right. Look for a punchable rock to release water — then turn around and head left to find the Pokéball.
Building the Smooth Tall Grass Habitat
The Smooth Tall Grass habitat requires 1 Smooth Rock and 4 patches of Dry Tall Grass. Create Dry Tall Grass by using the Leafage move on patches of grass that haven't been watered. Place the Smooth Rock on a dry area, then pile up the Dry Tall Grass around it.
Once built, Onix will move into the habitat and can follow you to rebuild the Withered Wasteland Pokémon Center using its Bulldoze specialty.