Mysterious giant chalk drawings of Santa have appeared on hillsides across the UK, sparking curiosity.

One of these festive artworks, complete with a 'Shh' gesture, is situated near Penrith in Cumbria.

However, the origin of the artwork is no longer a mystery.

It heralds the return of the Cadbury Secret Santa postal service.

This much-loved tradition allows people to send a free bar of Cadbury chocolate to a loved one.

The drawing signals the return of the Cadbury Secret Santa postal service (Image: KatieLee Arrowsmith/PinPep) Cadbury research shows that 42 per cent of people find receiving a secret gift more special than a traditional one due to the thoughtful consideration behind it.

This year, the process has been simplified with more QR code postal service posters across the UK.

Scanning a poster allows participants to meet the digital postman, Jeff, select the perfect Cadbury treat, and become a Secret Santa.

Newly introduced this year, to ensure as many people as possible can join in the festivities, is the Secret Santa chatbot.

Interacting with Jeff and providing one's location will help participants find their nearest poster.

The campaign, running until December 22, will release additional chocolate bars daily.

This gives thousands the chance to share a moment of generosity this Christmas.

The campaign runs until December 22 (Image: KatieLee Arrowsmith/PinPep) Nicole Dudley, Cadbury brand manager, said: "Cadbury Secret Santa is back, bigger and more magical than ever.

"To celebrate and add some festive cheer, giant 'Shh-ing' Secret Santas have been placed on hillsides – from the dramatic Devon coastline to the picturesque Cumbrian fells.

"Find a Santa, scan the code, and share a little Cadbury magic this Christmas."

Cadbury's research provides insight into why people enjoy secret gifting.

Forty-one per cent appreciate the surprise element, 38 per cent like imagining the recipient's smile, and 38 per cent say the joy can last for days.

It's considered somewhat magical by 29 per cent, while 26 per cent say it brings back childhood memories.

The service will offer bars of classic Cadbury Dairy Milk, as well as Cadbury Dairy Milk Oreo, Caramel, Whole Nut, Fruit and Nut, and Plant bars.

For those wishing to continue the fun, Cadbury bars and a selection of treats can be purchased via Cadbury Gifts Direct and gifted anonymously.

To find out more, visit their website.