Top tips for metal-detecting
14 October 2014 Last updated at 16:02 BST
The amateur metal detector, who unearthed a massive hoard of Viking treasure in Scotland, has been telling Newsround how he did it.
Finding buried treasure might sound like a dream but it's one that came true for Derek McLennan.
He dug up more than a hundred objects, including gold jewellery and a silver Christian cross.
Derek tells us how we can get involved in metal-detecting.