The gym statues.

I must admit, I never really clicked on these little guys when I went into the Pokémon gyms, heck I didn't even click on them til I was about 10 years old.

This little fact messed with my head, for someone who never clicked on them of course. In Pokémon Red and Blue, these little statues we're hiding something. You can actually when using the good or old rod, fish inside these statues and you will find nothing other than a level 5 magikarp.

Yup, I don't get how this works, the only thing I can think of is that you fish inside the mouth of the statue, and there's a secret pond? That's just my opinion. This wont work on Cinnabar gym or Saffron gym because their statues are smaller.