Pokémon FireRed and LeafGreen/Route 12-13

'You've liberated Saffron City from Team Rocket's mad scheme, and you could probably use a bit of a holiday. We hear the fishing is good down south of Lavender Town, so grab your Old Rod and get set to drown a few worms.'

'You ought to pack the Poké Flute, too. You won't be able to avoid Pokémon duels completely on this trip, but things will be far less hectic. Route 13 is more like a maze than a highway, but it is a pleasant place to walk and enjoy the great outdoors.'''

Sleeping Beauty
You'll need to use your Poké Flute to wake the blocking the path here. But first, visit the gate's second floor to get TM27. It contains (which, the stronger the friendship level of your Pokémon, the more powerful it is).

Woken Snorlax won't be very happy, but try to capture it. This is the only other Snorlax in the game, so if you didn't catch the one in Route 16, here's your last opportunity. With at least one Snorlax, you'll later be able to breed more. With the way clear, continue south to Route 13. After the Snorlax, get the Super Rod from a man in a house.

Items
Route 12 Route 13
 * TM27 (Given to you by the girl on the second floor of Lavender Town's gate)
 * Hyper Potion (Hidden near a fisherman)
 * TM48 (On a small island at the North of Route 12, through surfing)
 * Leftovers (Hidden and "buried" on the spot where Snorlax stands, unearthed with the ItemFinder)
 * Super Rod (Given to you by the Fishing Guru at a house south of Snorlax's spot)
 * Net Ball (one or more, up to a certain limit) (Given to you by the Fishing Guru for showing them a Magikarp and then, if possible, anytime for showing them a bigger Magikarp than the ones previously shown, theoretically limited to certain minimum and maximum sizes)
 * Iron (In the grass area accessible only by cutting a tree, south of the Fishing Guru's house)
 * Rare Candy (Hidden in the patch of grass on Route 12 (tree grass patches up from the bottom and two to the right from the left)
 * PP UP (Hidden in the hole in the south fence)

Leftovers is an important and popular item to be held by a Pokémon and that is geared toward advanced players, given the special way that it's hidden, requiring clearing out Snorlax. It recovers a Pokémon's health one bit at a time.