Reaching the historic Kanto region in Pokemon HeartGold marks the beginning of a massive post-game adventure that expands your journey significantly. After conquering the Johto League, trainers must find a path through a series of roadblocks to access iconic northern locations like Pewter City. Navigating this vast landscape requires completing specific infrastructural side quests before the path finally opens up for exploration.
Completing the Johto Campaign and Boarding the S.S. Aqua
Your journey toward the northern edge of Kanto begins immediately after defeating the Elite Four and Champion Lance at the Indigo Plateau. Once the credits roll, Professor Elm will summon you back to his laboratory in New Bark Town to hand over the S.S. Ticket. This key item allows you to board the majestic S.S. Aqua ship departing from the harbor in Olivine City.
The vessel takes you directly to Vermilion City, which serves as your initial gateway into the Kanto region. Upon arrival, you will notice that direct northward routes are temporarily blocked by unique environmental obstacles. To reach your ultimate destination, you must focus on restoring energy to the local transportation network first.
Restoring Power to the Kanto Region
From Vermilion City, trainers must travel north through Saffron City and continue onward until reaching the bustling streets of Cerulean City. Heading east onto Route 9 and surfing down the river of Route 10 brings you to the regional Power Plant. Here, the manager explains that a critical piece of machinery has been stolen by a shady character, halting all regional train operations.
To track down the culprit, return to the Cerulean City Gym and confront the rogue Team Rocket member hiding inside the building. After he flees to Route 24, defeat him in battle to learn the exact location of the hidden component. Retrieve the missing Machine Part from the gym life tube and return it to the Power Plant coordinator immediately.
Acquiring the Radio Upgrade in Lavender Town
Fixing the generator restores electrical functionality across the entire continent, allowing the Magnet Train to function between Johto and Kanto. Your next vital destination is the Lavender Town Radio Tower, located on the eastern side of the map. Speak with the station manager inside the building to receive the critical EXPN Card upgrade as a reward for your heroic efforts.
This special device expands your Pokegear interface to receive unique broadcasts that are unavailable anywhere else. This upgrade is absolutely necessary for clearing the final physical barrier standing between your character and the western mountains. Without this specific broadcast capability, your progress through the main storyline will remain completely stalled.
Clearing Diglett Cave and Reaching Pewter City
Travel back to Vermilion City and head east toward the massive sleeping Pokemon that is completely blocking the entrance to Diglett's Cave. Open your Pokegear radio interface and manually drag the tuning marker to the very top center to activate the Poke Flute channel. Interact with the slumbering Snorlax while this melody plays to initiate a battle and clear the cavern pathway.
Once the path is open, step inside Diglett's Cave and follow the long underground tunnels until you emerge on Route 2. From this exit point, simply travel north past the entrance of Viridian Forest to finally enter the peaceful streets of Pewter City. Here, you can challenge Gym Leader Brock to continue your quest for all sixteen regional badges.
