A new event is now live in Pokémon GO and invites trainers to Rediscover Kanto. By exploring biomes, they get to experience the refreshed visuals. This event started yesterday, April 22, and is expected to run until May 9.
For the duration of the event, Pokémon which were originally discovered in the Kanto region are going to appear in specific biomes. However, there may be some that could appear outside of these biomes especially during certain Pokémon GO Seasons or special events. Be sure to Work with other trainers and find as many biome types.
