A da Vinci code-style challenge that’s proved popular with Chester city centre visitors over the past three weeks is to be extended by popular demand.

Thousands of people have already attempted to unravel a series of riddles and unlock a 2,000-year-old city mystery following the launch of Deva Codex: Boar Quest at the beginning of August.

Developed by the team behind ‘Chester Unlocked’ – CH1ChesterBID and Big Heritage – the challenge has been a hit with people of all ages and is being extended by an extra week.

It will now run until Monday 31 August, with a thousand bags made available in locations across the city.

Marketing Manager at the city’s business improvement district CH1ChesterBID Julie Charlton, said: “Deva Codex has been incredibly popular so we’ve decided to extend it until the end of August to give as many people as possible the chance to take part. It’s a free city-wide mystery quest that anyone can take part in just by picking up a Deva Codex bag from outlets across the city. Anyone that completes the challenge is in with a chance of winning up to £300 in city centre gift vouchers.

“The back-to-school season is just around the corner now, so we hope this extra week gives families and friends one last opportunity to get together before the end of the holidays and have some fun in the city centre.”

Each of the free Deva Codex bags contains all the tools and clues needed to crack ten riddles and uncover the first in a trilogy of historical challenges set to run throughout the city centre in 2015.

People can take part any time between 9am-5pm (Mondays to Saturdays) and 11am-4pm (Sundays) and the bags will be available at various locations, including Chester’s History and Heritage Centre, Jigsaw, Chester Health Store and Sally’s Secret Garden (all situated in Bridge Street Row), Fat Face (Eastgate Street); Game (Foregate Street), Claire House (Frodsham Street), Grosvenor Museum (Grosvenor Street), Chester’s Visitor Information Centre (Northgate Street), Chester Cathedral (St Werburgh Street), St John The Baptist’s Church (Vicar’s Lane) and Corks Out (Watergate Street).

Those taking the challenge can gather clues and submit them online at www.chesterunlocked.com/devacodex/ to find out if they have unlocked the mystery.

By registering their answers and email address online, participants will be in with a chance of winning £300, £100 or £50 in retail vouchers to spend in-store in city centre retailers or venues (winners will be notified by email after 30th August).

This also gives them an entry to a Grand Prize draw, details of which are set to be announced later this year.

Find out more about the Deva Codex: Boar Quest at www.chesterunlocked.com/devacodex/ .

For more details on all things Chester Unlocked people can visit www.chesterunlocked.com .