There are only 16 gyms in total, (8 in Johto, 8 in Kanto) so there is no 17th gym.
*There used to be a gym on Cinnabar Island, until it was destroyed by the eruption of the Cinnaber Volcano-some time between Pokemon Red and Blue/Firered and Leafgreen and Pokemon Gold and Silver/Heartgold and Soulsilver.*
Not enough info: which gym leader?
you have to go to every gym in kanto a beat all the gym leaders
Janine I think
misty
All you have to do is get to Viridian City.
You beat the 6th gym leader.
Yes, to get to the Electricity Gym
In Johto, it is in Olivine City. In Kanto, it is in Fuchsia City.
The eighth gym leader still awaits, as well as the whole of Kanto.
he is Brock. hes in pewter city.
It is found in an ice cave below the fire type gym in Kanto.
You have to beat the first 3 gyms in Kanto before Erika will be in her gym. Erika's gym is the fourth in the series.