The fourth gym in the Kanto region is located in Celadon City. Celadon City is either the biggest town in Kanto or the second. You should now have the Boulder Badge, the Cascade Badge, and the Thunder Badge. This must mean your in Vermillion City. It is now time for you to head to Celadon City. In Celadon City there is literally a lot to do. For starters, the game corner is in Celadon City. The game corner is just a bunch of mini games and you earn coins. You can also just buy coins but the prizes are great. Such as the TM Flamethrower or the TM Ice Beam. Ice Beam is a powerful Ice type attack that can be taught to some Pokemon. Flamethrower is a powerful fire type attack that can be taught to some fire type Pokemon and even some Pokemon that aren’t fire type. The game corner is definetly something you should consider messing with when your in Celadon City. There is also a building where you can get the Tea. The Tea is what you give the gate guards to let you pass. I believe there is a few trees you need to use Cut on in order to enter the fourth gym.
Once you enter it will look like a complete garden. This is because the fourth gym is a grass type Pokemon gym. You will have to fight several trainers before you can get to the leader. I suggest you bring some Paralyze Heals, Full Heals, Antidotes, whatever you can to cure some status conditions. Because with some grass type Pokemon in this gym, they have some attacks like Stun Spore Sleep Powder and Poison Powder they can use that can be a nuisance on your part. Upon arriving to the leader, Erika. You should make sure your Pokemon are at full health and then challenge her to a match. The Pokemon are getting stronger for the gym leaders. Her first Pokemon is a Victreebel if you have fire type Pokemon now is the time to shine. Her second Pokemon is Tangela, which should be fairly easy to take down. The final Pokemon you have to fight is a Vileplume. Be careful because this Vileplume knows Stun Spore and Sleep Poweder. If you beat Erika you will get the Rainbow Badge. You will also now have half of the Kanto badges. Only four more to go and you can challenge the Kanto Pokemon League! Next up is the gym in Fuchsia City!