A postman turned map reader to deliver a letter which was marked only with a name and a drawing.
A map on the envelope had a dot drawn in north Cornwall and an arrow saying "Somewhere Here".
Postal workers in Bude, north Cornwall managed to pinpoint the right address and deliver the letter.
The letter to Peter O'Leary, was from a long-lost work colleague who failed to enclose his own address so Mr O'Leary cannot write back.
Bude's delivery office manager Andrew Lake said post workers worked out from the map the intended address was in Bude and then asked each other if anyone recognised the name Peter O'Leary.
Postman Eric Seymour realised Mr O'Leary lived on his round and said the customer was astounded when he handed over the letter.
"The customer was very impressed indeed and we were delighted to be able to deliver the item," said Mr Lake.
"I have come across vague addresses on letters such as the house two doors down from the church, but never a map."