Scunthorpe gold clues 'could take weeks to solve' Published duration 12 February 2017

media caption Five gold artworks are being hidden in Scunthorpe but finding them means cracking codes.

Clues in a public treasure hunt which will lead gallery-goers to five gold artefacts could take weeks to solve, the man who set them has said.

Treasure City is a project conceived by artist Luke Jerram where tiny treasures worth at least £1,000 each are hidden in Scunthorpe to be found and kept.

To find the pieces hidden around the North Lincolnshire town you will need to visit the 20-21 Arts Centre and study five paintings with codes on.

One is "extremely hard" to solve.

Bristol-based artist Luke Jerram is behind the project. He said: "There is no way I could crack the most difficult one, I could certainly crack probably two or three of the paintings.

"Some are really easy to decode, whereas the most complicated painting, it would take maybe a month for someone to perhaps work it out."

Mathematician and secret code setter Dan Fretwell works at Bristol University and is also employed by an unnamed government agency. He was called in to set the ciphers to encrypt messages telling people where to find the trinkets.

image caption The artworks are acrylic on canvas created by Vivienne Baker

"One of them is supposed to be ridiculously easy," he said.

"The final two in particular are much harder so we are expecting at least one of them to go unsolved for quite a while."

He added: "There's a real mixture including one that could be solved by a child, others that could be deciphered by the average person and more challenging puzzles for mathematicians or code-breaking enthusiasts to try their hand at.

"One of the puzzles may take some months or even years to solve, if indeed it is ever cracked."

The five objects cast into gold for the project are replicas of objects from North Lincolnshire Museum, and were made from gold worth £1,000. The finished pieces have been valued at between £2,500 and £4,500.

image caption Dan Fretwell set the ciphers for the coded messages working alongside Luke Jerram

image copyright 20-21 Arts Centre image caption The tokens are artefacts from North Lincolnshire Museum which were 3D printed and made into wax replicas before being cast in gold

image caption The five gold treasures are modelled on historic objects from the local area

"I had this idea to think about celebrating the history of Scunthorpe by taking five objects from the museum and created replicas in solid gold," Mr Jerram said.

"For me, Treasured City is a creative treasure hunt - a playful fusion of history, craftsmanship, mathematics, codebreaking, poetry and painting.

"I like the idea that ancient objects that were once hidden beneath the earth and were discovered and displayed at the museum are now being re-hidden.

"The art project is a way to consider and celebrate the original artefacts in relation to the history of Scunthorpe and the region."

There is a Janus train engine - as used in Scunthorpe's steel industry - a Viking brooch, an ammonite, a figure of a Roman ram and a 16th Century figurine.

The acrylic-on-canvas paintings have been created by Vivienne Baker, and all the clues are spray painted in gold.

image caption The artworks are acrylic on canvas and created by Vivienne Baker

image caption Luke Jerram has created sculptures, installations and live arts projects

You can watch more on BBC Inside Out Yorkshire and Lincolnshire on Monday 13 February at 19:30 GMT.