At
70, most people in the UK are settling into retirement but the Prince of Wales is working harder than ever.
More public engagements, more international tours and daily paperwork that often keeps him at his desk late into the night.
To mark the prince's birthday, CNN was invited to his Dumfries House estate in Scotland while he was visiting and to West Africa on an official royal tour.
Charles appears to be using his 70th birthday on Wednesday to highlight the work he has done so far as the longest-serving royal heir in British history.
By any measure he has used that time to redefine the role, making it a full-time job and expressing himself freely on the issues he cares about.
Many of his predecessors saw it as an opportunity to keep a low profile and enjoy the spoils of royalty before taking on the responsibility of the Crown.
Prince Charles poses for an official portrait to mark his 70th birthday in the gardens of Clarence House.
"I think you would easily understand the Prince of Wales if you came here," Kenneth Dunsmuir, director of the Prince's Foundation, the umbrella group for Charles' public projects, told CNN standing outside Dumfries House.
"It's very evident you can see very clearly what his work is and the variation of work, the variety that you see on the estate."
The house is best imagined as a fairytale 18th-century mansion at the center of a vast, immaculate estate with outbuildings humming with community activities.
There are no gates. Members of the public roam freely and it's not uncommon for them to encounter Charles himself as he goes about his inspections.
The Dumfries House in Ayrshire, Scotland.
CNN was shown a high-tech science lab nestled among trees, for visiting school groups, and an organic rare-breeds farm where the pigs live in plush, thatched pigsties.
In a renovated barn, unemployed adults were learning traditional crafts. All the projects speak to social and ecological issues close to the prince's heart.
The Prince's Trust is also well represented here with initiatives to support disadvantaged young people and help get them into work,
something desperately needed in nearby towns that have never fully recovered from the collapse of the coal mining industry in the 1980s.
Inside the house itself is a priceless collection of furniture bought directly from the cabinetmaker Thomas Chippendale in the 1750s by the fifth Earl of Dumfries.
The collection contains what's reputed to be the most valuable item of furniture in the world, a cabinet valued by the estate at $30 million.
One of the chairs in use during CNN's visit turned out to be worth a million dollars. When asked why such a valuable chair was being treated so casually, a member of staff replied: "Because they are here to be used."
Encouraged by the prince, this un-precious philosophy is what drives the place. It's meant to be a living, breathing project that is not only part of the community but adds to it.
Prince Charles stepped in to save the estate from the seventh Marquess of Bute who couldn't afford the upkeep. It was renovated and reopened by the prince as a visitor attraction.
Dumfries House is now the second-largest employer in the county, after the local authority, and has even funded a new town hall and outdoor swimming pool in the nearby town of New Cumnock.
Every Friday, the prince is sent a report on the estate running to dozens of pages and he returns it with notes the next morning.
"The signs were there from young adulthood -- his concerns about social issues, community issues and ecological issues," Dunsmuir said.
"All that's happened is that he's got more and more involved and has had the time to develop these ideas and take them further, due to the length of time that he's been Prince of Wales.
What I'd like to think is that in bringing together so many strands into the Prince's Foundation of his charitable initiatives, that this (Dumfries House) is a fantastic physical legacy of that work that will always be here and always remain."
While Dumfries House may be the project that best symbolizes Charles' legacy as Prince of Wales, we shouldn't take it as an indication of what sort of king he will be.
A senior aide said the prince feels a duty to use his platform now to promote his causes before he becomes head of state.
He knows the two roles are distinct and it is "his clear wish and intention to change his approach in the next role."
Without doubt, he has a lot to live up to. His mother, Queen Elizabeth II, is revered for the way she has steadily gained popularity during the course of her reign despite the collapse of the British Empire and a general loss of deference in society.
She has modernized and stayed relevant by embracing public walkabouts, mass media and charitable work.
She has rarely expressed any opinions, let alone political views, so we never know quite what she is thinking.
We know what the Prince of Wales thinks about a wide range of issues so he is already a more divisive figure and that won't simply be forgotten when he takes the throne.
He was ahead of his time on many issues, warning as far back as the 1970s of the dangers of climate change before it became a mainstream issue, and he continues to do so now when, for many, it's become a political issue.
A giant portrait of Prince Charles outside a Young Entrepreneurs Event in Accra, Ghana, on November 5.
At a speech in Accra, Ghana, last week, the Prince said,
"I know, Mr. President,
that you share my determination that the Commonwealth should strive for renewed relevance in the lives of its citizens and should draw upon its unparalleled networks of professional expertise to offer practical solutions to some of the most pressing challenges of our time,
many of which are increasingly deep-seated and deeply integrated.
No issue is more pressing, it seems to me, than that of climate change.
The recent report of the Intergovernmental Panel on Climate Change,
which provided stark and alarming evidence that even 1.5 degrees of warming will mean catastrophic damage to the planet's ecosystems, sent a clear signal that we must all surely heed."
Charles will become head of the Commonwealth when he becomes king.
He made the case again in Nigeria with a group of powerful regional leaders.
After the meeting in Abuja, the Emir of Kano was positive about the Prince's interventions, telling CNN: "He's been talking about climate change.
He's been talking about demographic implosions. He's been talking about town planning and we do not make the connection between these three issues, for example, and some of the conflicts we see."
Prince Charles attends a meeting with regional leaders in Abuja on November 6.
There was particular interest in his work on youth unemployment, which is rife in the region, though the prince wasn't able to see as much of the country as he had hoped, to his frustration.
Because of security concerns, the British government called off a visit to Jos, a city in Central Nigeria that has been the scene of deadly clashes between Christians and Muslims.
"The only sad thing for me was not being able to go further into other parts of Nigeria," Prince Charles told CNN.
"It is such a vast country and obviously there are so many other states and interesting areas.
I know many are facing different challenges and other opportunities, so it was a pity not being able to do that, but otherwise it's always marvellous coming here because people are so friendly.
I'm always intrigued by the way so many of these young, for instance, are developing really interesting ideas that they can turn into businesses and things like that,
helping to tackle some of the real issues we face, particularly around the environment and waste and goodness knows what else. Very ingenious characters."
At 70, Prince Charles has given his future role "a lot of thought," the senior aide told CNN, particularly what he will and won't be able to speak about, but it "doesn't weigh heavily" on his shoulders.
If he feels any pressure, it appears to be completing his work as Prince of Wales, which is a role he has made his own.
He's redefined the responsibility that comes with being heir and in that sense he has already left a legacy.
