Walkthrough
After defeating Giovanni and having earned your final Gym Badge, you will be free to proceed to Victory Road in hopes of reaching the Indigo Plateau so you can challenge the Pokemon League. However, if you haven't done so already, it would be wise to head to the Power Plant - not accessible until you have the Sea Skim Technique - in order to catch the Legendary Pokemon Zapdos. To reach the Power Plant, all you must do is surf the waters found on Route 10 (east of Cerulean City, near Rock Tunnel); they will lead straight to the Power Plant. On top this being the home of Zapdos, loads of other Electric Type Wild Pokemon can also be here (as well as one trainer).
Interactable Pokemon
Electrode (Appear As Poke Ball Items): Level 42
Wild Pokemon
Standard Walking:
Koffing (25%): Levels 37-42
Magnemite (23%): Levels 37-42
Voltorb (23%): Levels 37-42
Electabuzz (14%): Levels 37-42
Magneton (5%): Levels 37-42
Electrode (5%): Levels 37-42
Weezing (5%): Levels 37-42
Standard Walking - Special Spawns:
Chansey: Levels 37-42
Trainers
Coach Trainer Mabel: Level 44 Omastar, Level 44 Kabutops, Level 45 Aerodactyl
Obtainable Items
Max Revive: Near Sandbags By Entrance
Rare Candies: Defeat Coach Trainer Mable
X Sp. Def: Near Coach Trainer Mable
Rare Candy: Near Large Southern Machine
TM38: Near Southern Sandbags By Oil Drums
Max Potion: Near Northeast Sandbags
Thunder Stone: Near Northeast Sandbags
Paralyze Heal: Near Machine By Electrode (Disguised As Poke Ball)
Max Potion: Main Oil Drums Area
Voltorb Candy: Hidden In Oil Drum Rows
Voltorb Candy: Hidden In Oil Drum Rows
Voltorb Candy: Hidden In Oil Drum Rows
Voltorb Candy: Hidden In Oil Drum Rows
Pretty Wing: Hidden Near Chair By Machine At End Of Power Plant
Post Game
Walkthrough
After defeating the Elite Four and starting the Master Trainers Challenge, you will find just one Master Trainer within the Power Plant for you to defeat.
Trainers
Scientist Humphrey (Master Trainer): Level 70 Voltorb