With the Go-Goggles, you can finally venture into the windswept desert on Route 111. The powerful sandstorm deters most would-be explorers, so no one has yet claimed the valuable treasures lying among the dunes.
The unusual arrangement of stones to the south is known as the Desert Ruins. It is believed to mark the resting place of a legendary Pokémon. But with the entrance sealed, you won't be able to investigate until later.
Mirage Tower (optional)
Mirage Tower, 1F
Mirage Tower, 2F
Mirage Tower, 3F
Mirage Tower, 4F
Mirage Tower is an elusive building located just inside the desert's southern entrance. The tower disappears and reappears as would-be explorers visit and leave the route. The ancient structure shows its age, with unstable floors and fallen rock scattered about. Progressing past these obstacles requires using the Mach Bike and Rock Smash.
The tower's top floor holds two treasures from the ancient past. The Root Fossil and Claw Fossil belong to two species that once lived in the primordial ocean. The researchers at Devon Corporation back in Rustboro are able to revive any Fossil they receive into a long-lost Pokémon. The Root Fossil becomes the Rock/GrassLileep, while the Claw Fossil turns into the Rock/BugAnorith. Choose carefully! After removing either one, the tower begins to shake, and you fall from the building, landing just outside the entrance. The tower disappears down into the dunes, and the remaining Fossil falls away into the shifting sands.
Back to Petalburg City
Now that you've claimed your fourth Badge and combed the desert for treasure, your next stop is Petalburg City. The city is far to the southwest, but there are multiple ways to get there.
Once in Rustboro, be sure to stop by Devon Corporation. Take your Fossil to the second floor of the Devon Corporation building, and give it to a scientist there for him to restore. Exit the room, come back in, and receive your newly resurrected Pokémon.
Petalburg City Pokémon Gym Leader: Norman
A man in pursuit of power!
The Petalburg Gym, which specializes in Normal-type Pokémon, is styled as a traditional dojo with multiple rooms. Each room has a single Trainer who uses a certain strategy. The sign on each door gives a clue to the strategy of the Trainer in the room behind it. Rather than relying on items, each Trainer's strategy depends on the moves of their Pokémon. The first two rooms beyond the lobby are labeled "Speed" and "Accuracy". The three rooms farther on are named "Confusion", "Defense", and "Recovery". The final two rooms before the Gym Leader are labeled "Strength" and "One-Hit KO". A minimum of three Gym Trainers must be defeated to reach the Gym Leader. Fighting types like Combusken and Breloom will give you the upper hand here.
In the final room, your father has been waiting for you. Now that you have earned four other Badges, he is ready to accept your challenge. Norman leads with his Spinda; Teeter Dance allows it to confuse the target. Fighting Pokémon should watch out for its Psybeam! His Vigoroth is so restless that it can't sleep, due to its Vital Spirit Ability. While not a serious threat, it may land a critical hit with Slash. Linoone can be a serious problem, as Belly Drum halves its HP in order to boost its Attack by a whopping 300%! Luckily, the move fails if the user's HP has fallen below 50%. Slaking usually leads with Yawn. Although Slaking can use its extremely dangerous 160 base Attack stat to overpower most Pokémon, its Truant lets you completely shut it down with Dig or Protect. Additionally, if you switch out your Pokémon (possibly to keep Yawn from working), your replacement will be safe for one turn. All four of Norman's Pokémon know Facade, which doubles in power if the user is Burned, Poisoned, or Paralyzed, though the Attack penalty incurred by sustaining a Burn still applies.
Afterwards, your father awards you the Balance Badge, which boosts your Pokémon's Defense by 10% and enables the use of Surf in the field. He also hands you TM42 (Facade) as a gift. Just then, Wally's father bursts in, claiming that he's got something to give you. He leads you next door to his home, where he apologizes for his hasty behavior. He tells you that living in Verdanturf has done wonders for Wally's health, and he gives you HM03 (Surf) as thanks for helping the young Trainer. In battle, Surf is a strong Water-type attack; in the field, it allows you to cross bodies of water. If you're not in a hurry, then consider using your new HM move to explore some of the water routes that Hoenn has to offer.
Starting now, your PokéNav will start showing that some trainers want rematches with you. They will be marked by a square Poké Ball in the Match Call feature. Note that the more often you travel on the route or cave where any of these unique Trainers are located, the greater chance the trainer in that area will be ready for a rematch.
Now that you can use Surf (optional)
You can meet many new trainers and find many new items by crossing the ponds and seas scattered throughout Hoenn. When you're ready to cross the sea, approach the coastline and use Surf. Hop on your seafaring Pokémon's back to glide across the water. While Surfing, it is impossible to use the field moves Cut, Strength, or Rock Smash; however, severalothermoves are allowed. The Itemfinder can't be used while crossing the waves, but you can use an Escape Rope or a fishing rod while doing so.
Also now that you have Surf, Mr. Briney will no longer transport you between his house on Route 104 to Dewford Town, or Route 109, instead you'll have to transport yourself using Surf.
Here there are two Swimmers in the middle of the river, just waiting to battle you. These trainers use Pokémon of considerably lower levels than the last ones you faced, so they shouldn't be much of a challenge. However, if they look at you at the same time, the battle will turn into a Double Battle.
You can now fully explore the route by using Surf. Surf north past Meteor Falls and make landfall at a small beach. Fight a few trainers as you navigate further north through a maze of trees. At the very northwest corner, you can find Route 115's one tiny patch of tall grass.
The unusual arrangement of stones in a corner in the northwest is known as the Island Cave. It is believed to mark the resting place of a legendary Pokémon. But with the entrance sealed, you won't be able to investigate until later.