you have to beat the gym, use cut on the shrubs outside, and go in the door. Ta da!
Eterna City pokemon center. The first chick by the door if I recall correctly.
release the lake Pokemon in the Galatic HQ building
yes it is you have to go upstairs into the room with the television press A on it then you will eventually battle rotom Also, during the dates of April 20th and may 12th, (in the Mystery gift box) you are able to receive rotom's "secret key" that can unlock a room in the eterna building. this enables you to change rotom's form You can also go to the third floor of the T.V. company in Jubilife City. Talk to the producer there and answer his first question with "Everyone Happy" and his second question with "WIFI Connection" to get the key. The room is on the top-left corner of the first floor in Team Galactic's Eterna building. You might miss it though because the door looks like a wall.
Go into the Old Chateau (top of Eterna Forest). Go to the door at the top on the 2nd floor. take the 4th doorway on the left (or 2nd from right). It's inside the T.V.
The door can only be unlocked through a Nintendo event to get the legendary Pokémon: Drakrai
It opensa secret door in the Eterna Galactic building where you can change rotoms forme.
There is go to the Galactic buliding WITH the secret key AND ROTOM.So goto Eterna city and the fancy bad building and youfindasecretdoor
It,s in eterna city
You can get it from Bebe(next door to the Pokemon center in Eterna city), or you can check out the trophy garden, it will appear there occasionally.
Eterna City pokemon center. The first chick by the door if I recall correctly.
got to the house next door to the eterna Pokemon center and talk to the old guy
You get underground by getting the Explorer Kit from the Underground man in Eterna city who's next door to the Pokemon Center.
in eterna forest you need to get cut you can also find rotom at 12am if you go to the door upstairs first door two the left
To transform Rotom into one of its new forms, the player must have a Secret Key (a key item distributed by Nintendo through Mystery Gift). Taking the key to the Galactic Eterna Building in Eterna City unlocks a door to a hidden room on the ground floor (left of the television) that houses the appliances that Rotom can possess.
I Have Pokemon Pearl But Either Way I Think It's The Same... The Only Way To Get It Is That You've Had To Seen At Least 35 Pokemon Before Or When You Get To Eterna City Defeat Team Galactic But Get Eterna Badge First! Then When You've Met 35 Pokemon And Get Your Bicycle Then You Go To The Door Way To The Cycle Road And There You'll Meet Lucas's/ Dawn's Father And There He Will Give You The EXP.SHARE
release the lake Pokemon in the Galatic HQ building
i don,t no but if your talking bout how to go underground in Pokemon platinum you have to go to eterna city and enter the house next door to the Pokemon center. hope i helped! :D