Things You'll Need
Instructions
Go to the roof of the department store in Celadon City.
Examine the vending machine. The purchase menu appears with three drink options.
Press "Fresh Water" to purchase it from the vending machine. You can buy any of the drinks from the vending machine to get the guards to unlock the gatehouse door. "Fresh Water" is the least expensive drink, which makes it the best choice.
Go to the gatehouse on the west end of Route 8.
Talk to one of the guards. Agree to give him a drink if he unlocks the door.