at the west entrance right when you walk in
it doesnt exist in platinum! dumbo!
Go to the spot in Mount Moon where you got the Fossils. Go back down those stairs and to the right, you'll see a rock. If you press A on it you get a Moon Stone. :D -If you've already found both of the moon stones in Mount Moon, try the Rocket Hideout, Route 2, or the Mansion. Of course, you could always trade for one.
mount moon isn't in Pokemon diamond. it would be in FR and LGMount moon is located in Kanto, not Sinnoh where Diamond is set. You may be thinking of Mt. Coronet which is accessible from Orebrough or Hearthome city.
if you go to the top you can battle master trainer red, and if you go to the bottom you can catch moltres
The Pond is only for decoration if you come back to mount moon on a monday night after 8 o 'clock the moon will reflect off of the pond and Clefairy will dance one of them will leave behind a moon stone hope this helps- Signed The Girl Pokemon Master, BailiB
to mount moon
Once you've met your rival at mount moon, go to the dragons den. There you will have a double battle with your rival against Lance and Clair.
Battle your rival, find two clefary's and a home
he is in the beginning of mount moon his highest i level 50
Just inside the route 4 entrance to Mount Moon
Don't go where the rival events going to be at that time
mount moon the pewter town entrance and after that i think hes in dragon dens
Dragon's den in Johto, You'll then fight Clair and Lance with the Rival
Owen does not have a rival in ToT. But in AP Kathy is your rival for Owen.
Go through Pewter City and head east to until you find the Pokemon center. Then head into the cave. You've made it to mount moon
go to mount moon and walk around
Pokemon league After beating him in mt moon Go up the stairs Untill your rival comes NOTE: he is only there on certain days this also works for heart gold