it took me a bit to get to lvl 100 but i found the best place to level up was the elite 4.
you can go back to the elite 4 as many times as you like and to double the exp that you earn put the EXP SHARE on your Pokemon that you are using to fight. e.g. Blaziken
hope this helps :)
Thanks!
The only good place to train is the elite four unfortunately.
elite 4
the elite 4
battle the elite four
elite 4 or mt silver
elite 4
If you are strong enough the elite four and alder.
The best place I know is victory road
Seven Island if you don't include the elite four.
give beautifly exp share and take him/her to the elite four and train there.
the elite 4 or the places with the highest lvl wild Pokemon in them
Train with the Elite Puffles Train with the Elite Puffles