The coastguard office overlooks South Stack

Twelve-year-old Sheena jumped to the rescue when she spotted Lacey, a golden Labrador, on a rocky slope in Holyhead.

Lacey was lying trapped at the bottom of a gully in a pool of water. But Sheena found Lacey's owner, kept on barking and directed her to the spot.

Holyhead Coastguard said: "She is very lucky that the other dog found her."

A spokesman said Lacey would not have been able to climb out of trouble herself after falling down the cliff on Monday afternoon.

He said: "One of our rescue team climbed down to the dog and set up a harness and rope system to winch her back to the top.

"The dog was shivering from the cold and a bit shocked and nervous but she did not seemed to be hurt and was wagging her tail."