Celadon City is one of the largest cities in the Pokémon FireRed game world and is also where you'll find a wide variety of sights. Unfortunately, however, getting there isn't very easy. You can start your journey to Celadon City immediately after defeating the city leader of Orange City. Along the way to your destination, you will find many useful tools and numerous Pokémon specimens. Once you arrive in Celadon City, you will be able to get the "Ghost Probe" which will give you access to the "Pokémon Tower".
Steps
Part 1 of 4: Leave Aranciopoli
Step 1. After defeating the Orange City Gym Leader, head to "Route 11"
On the way to Celadon City, you will be led through a large cave and the "Flash" move will make crossing a lot easier. The "Route 11" starts from the east side of Aranciopoli.
Step 2. Get to the other end of "Route 11", then enter the "Diglett Cave"
At the exit of this cave, you will find "Route 2".
Step 3. After capturing 10 different Pokémon, talk to Professor Oak's assistant
He will give you the move "Flash" (HM05): essential to be able to face the "Rocky Tunnel". In order to get this special move, you need to catch at least 10 different Pokémon.
Step 4. Head to Heavenly City
You need to return to Aranciopoli, then continue north until you reach the city of Celestopoli.
While in town, replenish your potion supplies. Inside the "Rocky Tunnel" you will have to face a total of 15 trainers, so having enough potions will be of great help. Some "Escape Ropes" and some "Repellents" may also be useful
Step 5. Walk to the east side of the city, then go through the burglarized house and use the "Cut" move on the small tree blocking the passage
This will give you access to "Route 9", which will allow you to reach the "Rocky Tunnel".
Step 6. Follow "Route 9" and "Route 10"
Along the way you will have to face several opposing coaches. Try not to use all the healing tools at your disposal during the clashes, you will need them inside the "Rock Tunnel". Once you take "Route 10", you will find a Pokémon Center directly to the south.
Step 7. Enter the Pokémon Center, then heal all Pokémon on your team
The "Rocky Tunnel" that awaits you ahead is long and difficult; Before continuing, make sure your Pokémon have rested and recovered in the Pokémon Center.
Part 2 of 4: Go through the Rocky Tunnel
Step 1. Once inside the tunnel, use the "Flash" move
When used outside of combat, this move has the ability to illuminate the surrounding space; allowing you, in this case, to walk without problems along the "Rocky Tunnel".
Step 2. Locate the staircase on the east side
To avoid ending up in a dead end, you will have to go down slightly and then go up and find the ladder; in this way you will reach the lower floor.
Step 3. Walk left, then follow the stretch of tunnel back and turn right
In this way you will reach a second ladder, which will take you back to the first superior.
Step 4. Walk south (towards the bottom of the screen), then turn right to meet the next ladder
The latter will lead you back to the lower floor.
Step 5. Walk along the path to the left, then head north (towards the top of the screen)
This way you will reach the last ladder.
Step 6. Examine the cave wall to the south to locate the exit
Once outside, you will find yourself on the south side of "Route 10".
Part 3 of 4: Reaching Celadon City
Step 1. Enter the city of Lavandonia from the south side
The city of Lavender Town is characterized and dominated by the "Pokémon Tower". You will not be able to access the upper floors of the tower until you get hold of a "Ghost Probe". You can get this type of tool in the city of Celadon City.
Step 2. Exit Lavender Town by taking "Route 8" to the west
At the west end of "Route 8" you will reach the entrance gate of Saffron City. Unfortunately, the gate will be locked, so you will be forced to find another way into the city.
At this point, you can capture a wild Growlithe specimen by using the "Cut" move on the tree to gain access to the fenced area. This Pokémon will be very useful to you when you have to face the gym leader of the city of Celadon City
Step 3. Enter the building north of the access gate to Saffron City
From this point you will have access to the "Underground Way". This tunnel brings you back to the surface at "Route 7", exactly at the gates of Celadon City.
Step 4. Along "Route 7" you have the opportunity to train your Pokémon
The small patch of grass you find along "Route 7" is a great place to train your Pokémon a bit before taking on the Celadon Gym Leader.
Step 5. Enter Celadon City
Head to the upper left corner of "Route 7", from there you will be able to enter the city of Celadon City. It is one of the largest cities in the Kanto region, so you will have plenty of activities to do.
Part 4 of 4: Exploring the City of Celadon City
Step 1. Visit the Celadon "Shopping Center"
It is one of the best places in the game to buy useful tools to continue the adventure. Inside the "Mall", you can get a wide variety of "TM", stones and healing tools. You can also purchase "Mega Balls", which are perfect for quickly catching elusive Pokémon.
Step 2. Visit "Villazzurra" to unlock access to Saffron City
Talk to the elderly lady you find on the first floor of the villa to receive a tea-based drink; by taking the latter to the police officer in the Saffron City access station, you will get the green light to enter the city.
Step 3. Obtain an Eevee specimen
If your Pokémon team has 5 or fewer items, you will be able to get an Eevee specimen by entering the back door of "Blue Villager". It will be delivered to you by a strange man. Expose your Eevee to radiation from a "Waterstone", "Thunder Stone" or "Fire Stone" to see it evolve into a Vaporeon, Jolteon or Flareon respectively.
Step 4. Defeat the Celadon Gym Leader:
Erika. Most likely he is one of the easiest gym leaders to beat among those you will face; this is because Erika specializes in "Grass" type Pokémon, which have a large number of vulnerabilities. "Fire", "Ice", "Beetle" and "Flying" type Pokémon are found to be very effective against Erika's Pokémon.
Step 5. Take on "Team Rocket" inside the "Celadon City Casino" to get "Spectrum Probe"
Enter the casino and examine the poster located inside the room. It actually hides a switch that is used to access the "Rocket Refuge". Before you can face Giovanni, the leader of "Team Rocket", you will have to explore the different floors that make up the hideout and beat several "Rocket Recruits". Giovanni's Pokémon team is particularly vulnerable to "Grass", "Water" and "Fighting" -type Pokémon. Defeating Giovanni will cause him to lose his "Ghost Probe".
Step 6. Collect Giovanni's "Ghost Probe", then return to Lavender Town
You can use this tool to be able to see the ghosts that populate the "Pokémon Tower" and access the upper floors of the building.
