its in the sea route between petalburg and dewford on the left. you have to search a bit.
The only way to get Regice on pokemon diamond is to transfer them from Ruby, Emerald, or Sapphire.
migrate it from ruby/sapphire.
you cant get regice in pearl you haft to migrate him from sappire ruby or emerald
there is not regice in pearl. but if you have ruby, emerald, or sapphire you could trade regice,regirock, and registeel to get rigigious.
Transfer from Ruby, Sapphire, or Emerald.
Legindaries are Groudon,Rayquaza,regice,registeel,regirock.If you want more go get a Pokemon ruby guide book
Regice can not be caught in HeartGold or SoulSilver. It can however be caught in Platinum, Ruby/Sapphire, and Emerald.
Migrate from Ruby Sapphire or Emerald.
in ruby there's groudon, raquaza, regirock, (if you consider it a lengendary) regice, and regirock
You can get the regice, regirock, or registeel.
Regice is in route 105 in the island cave with those 5 big boulders around it.
You can't, it must be traded from ruby, sapphire, or emerald.