Walkthrough: Just south of Heahea City is Diglett Tunnel. This small cave will lead you straight to Route 9, which just so happens connects to Konikoni City (the home of Kahuna Olivia). In Diglett Tunnel, you will officially be introduced to the Aether Foundation (who will warn you about Team Skull). You will also battle Team Skull with Hau here.
Wild Pokemon:
Initial Pokemon (Levels 20-23): Zubat(60%), Diglett(30%), Larvitar(10%)
SOS Pokemon #1 (Levels 20-23): Golbat, Diglett, Larvitar
SOS Pokemon #2 (Levels 20-23): Zubat, Diglett, Larvitar
Rustling Spots (Levels 20-23): Diglett(100%)
Trainers:
Worker Vaclav - Level 22 Archen
Worker Frank - Level 22 Shieldon
Worker Jeff - Level 22 Diglett, Level 22 Diglett
Team Skull Grunts - Level 23 Salandit, Level 23 Ekans
Items:
Hyper Potion - Near Western Wheelbarrow
Max Ether - Defeat Team Skull
Dusk Ball - Near Worker Frank
Fire Stone - Behind Western Tauros Rocks
Escape Rock (Hidden) - Near North Entrance
X Attack (Hidden) - Near North Entrance
Nugget (Hidden) - Near Southern Wheelbarrow