You have to get enough ribbons.
At the resort area
in the servile area
yes in the resort area
Go to the resort area
You can get a syther above the Resort Area. there will be a patch of grass above the Resort Area.(You have to have a pokeradar)
To get into this exculsive club, you must have access to the Resort Area. Next thing, you must have 20-30 ribbons in total on all your Pokemon. After this, walk inside the building and the girl will then be about to take you out of the building when she sees how many ribbons your Pokemon have. Now, you have access to the whole building, including extra expensive ribbons for your Pokemon and a Relaxing Room for your Pokemon.
The Resort Area is located on an island on North Sinnoh off of route 229. There are not Poke-Marts in the Resort area or battle gyms.
the really long grass in resort area no pokeraider
You can't only in Pokemon Platinum unfourtunatly.
yes just outside the resort area
resort area in the pond around the tree
the land behind the pokemon leage is the battle area, survivel area and resort area