Walkthrough
The Viridian City Gym is home to Gym Leader Giovanni,the leader of Team Rocket, a Ground Type Pokemon Trainer. In order to gain access to this Pokemon Gym, you must first defeat the other seven Pokemon Gyms and complete your mini adventure in the Sevii Islands. Similar to the Rocket Hideout, you will use spinning tiles to work your way through the gym towards Giovanni, defeating the trainers that stand in your way of do so.
Tamer Cole: Level 39 Arbok, Level 39 Tauros
Black Belt Kiyo: Level 43 Machoke
Cool Trainer Samuel: Level 37 Sandslash, Level 37 Sandslash, Level 38 Rhyhorn, Level 39 Nidorino, Level 39 Nidoking
Cool Trainer Yuji: Level 38 Sandslash, Level 38 Graveler, Level 38 Onix, Level 38 Graveler, Level 38 Marowak
Black Belt Atsushi: Level 40 Machop, Level 40 Machoke
Tamer Jason: Level 43 Rhyhorn
Cool Trainer Warren: Level 37 Marowak, Level 37 Marowak, Level 38 Rhyhorn, Level 39 Nidorina, Level 39 Nidoqueen
Black Belt Takashi: Level 38 Machoke, Level 38 Machop, Level 38 Machoke
Because Giovanni specializes in Ground Type Pokemon, he is extremely weak against Water Type Pokemon. Fire Types, Electric Types, Poison Types and Steel Types are extremely weak against Ground Type Pokemon, so avoid using them if you can. Defeating Giovanni will earn you the Earth Badge and TM26 (Earthquake), as well as Giovanni deciding to disband Team Rocket (though that won't stop his other colleagues). (The Macho Brace can also be found within this Pokemon Gym by using the ItemFinder.)
Gym Leader Giovanni: Level 45 Rhyhorn, Level 42 Dugtrio, Level 44 Nidoqueen, Level 45 Nidoking, Level 50 Rhyhorn
Now that you know about the eighth Pokemon Gym, Click Here to learn about the Elite Four!