Route 3 is a rugged route that links Pewter City to Mt. Moon in the east. Just outside the city is a large crater where several meteorites have fallen. These rocks seem to emit a strange cosmic energy that may influence a certain species of Pokémon.
Mt. Moon once featured a large cave network, but recent collapses have left only a single chamber connecting Route 3 to Route 4. Silver appears not far from the entrance and challenges you once again. After he leaves, climb the ladder to the east.
From 8:00 PM Monday through 4:00 AM Tuesday, six Clefairy appear in the field to the west. Four of them begin dancing around the pond, which shows a reflection of the full moon. When you enter the field, they get startled and run away, leaving behind an item that turns out to be a Moon Stone. The group returns to worship the moon every week.
Enter the south side of the cave for a shortcut to the exit.