Where are the ring in Lord of the Rings battle for Middle-earth 2

It is not in a certain place Gollum has it and you need to find him and defeat him to get the ring then you have to take it back to your castle.

The One Ring is held by Gollum, an NPC. He runs around the map invisible until you get close to him and he will reappear. Once you defeat him, you can take the One Ring back to your castle and lock it away. Once there, you are granted with either one of two ring heroes, Galadriel (Good side) or Sauron (Evil Side). It depends on which side you have chosen to play as. Both are extremely powerful and can do major damage.