You have to go to Wyvern Hill and on the last floor you'll see a door with a ket hole(Make sure you bring a key to open it) If thats to hard(Since its on like the 40th floor and thats hard for some people) I have a wondermail so you can get it more easily!

Wondermail password: 4?1N WJF? 4P?0
N1?Y 64N6 4T?W


Don't worry! It's only on the first floor of Tiny Woods.

ok thx just doin it and worked now to get groudon and rayquaza

HM fly is in Wyvern hill 30th floor you need a key from solar cave.