there is no 16th gym in soulsilver u dope....
Well after you defeat 15 gym leaders in Pokemon HeartGold / SoulSilver go to Cinnabar Island and talk to Blue.
defeat gym leader.
you have to beat the last gym leader
train them a lot to around 20
I'm not sure but I think you have to defeat the fourth or fifth gym.
The 16th gym leader is Blue. You can only fight him after you win all 15 gym badges. after you get all 15, go to cinnabar island, blue will be there. show him your badges and he will return to the gym so you can fight him
beat blue to get it.
you defeat one of the gym leaders and then go to the flower shop and a girl will give it to you
Go to the gym in Vermillion City in Kanto and battle Lt. Surge, the Gym Leader. He'll give you the 9th Gym Badge after you defeat him.
After you have beaten the Mahogany (yeah that's how its spelled :P) Gym, you must go to Goldenrod City and defeat Team Rocket.
defeat all 7 gym leaders in kanto then the old man will move
yes, and you have to battle her to get your 16th gym badge