William and Kate release romantic image on low-key anniversary
The heir to the throne and Catherine, also known as Kate, were pictured looking out to sea on a shoreline with their arms around each other.
The couple were dressed casually in open-necked shirts, jackets and boots, with Catherine showcasing a new light brown hair colour.
The picture was posted on their official social media accounts with a heart emoji and signed with their initials.
"Wonderful to be back on the Isle of Mull. Thank you to everyone for such a warm welcome W & C," it said.
The couple opted for a low-key anniversary celebration including a stay at a self-catering cottage on the secluded west coast island.
They married on April 29, 2011, at London's Westminster Abbey in a ceremony watched by tens of millions around the world.
Community and environment
During the two-day visit to the islands of Mull and Iona, William and Catherine spent time with members of the local communities "reflecting on the power of social connection and the importance of protecting and championing the natural environment" -- two subjects close to both their hearts, according to their Kensington Palace office.
They previously visited Mull when they were students at Scotland's University of St Andrews where they met.
The island, Scotland's fourth-largest, has a population of around 3,000 people, and is known for its fishing and farming communities.
Engagements included a visit to an artisan market in the Mull town of Tobermory and a local croft where they learned about sustainable farming and hospitality.
On Wednesday they joined children and parents at a woodland play group offering den building, nature trails and animal tracking.
The issue of childrens' early years development has been described as mother-of-three Catherine's life's work by aides.
She has also stressed the healing role of nature in her own recovery following a cancer diagnosis last year.
Catherine, whose formal title is Princess of Wales, revealed in January she was "in remission", having announced in March last year that she had been diagnosed with an unspecified form of the disease and was undergoing chemotherapy.
She has since returned to frontline public duties but with a slimmed-down schedule and shorter engagements.
Her diagnosis came as William's father King Charles III also battled cancer for which he is still undergoing treatment.
The royal couple were due to wrap up their trip later Wednesday with a visit by public ferry to the neighbouring island of Iona.
Although Iona has a population of only around 170 people it receives around 130,000 visitors a year.
har/jkb/phz