Prince Charles and Camilla's Welsh home is said to be almost entirely sustainable - complete with a wood-chip boiler for heating and hot water.
The royal couple's most well known home is Clarence House, however they own other properties across the UK.
The Prince of Wales and the Duchess of Cornwall also have the Scottish Birkhall estate and their Gloucestershire home Highgrove House.
But their most sustainable property is Llwynywermod, the royal estate which is set in the village of Myddfai, Carmarthenshire, close to the scenic Brecon Beacons.
Llwynywermod is a huge farm which includes multiple buildings and was bought by Prince Charles back in 2007, costing him £1.2 million, OK reports.
The Llwynywermod estate boasts an impressive three cottages, a Grade II-listed barn, the main house and plenty of land.
Since buying the property, Prince Charles has personally overseen the developments, ensuring it was as sustainable as possible, reports say.
For the renovation, Charles reused materials such as locally sourced Welsh slate and lime plaster and hired local labourers to transform the home into a 'sustainable haven'.
All of the farm's heating and hot water comes from a wood-chip boiler and there is even a tank for rainwater storage.
The home has perfectly landscaped gardens at its front and back with plenty of vegetable patches for growing fresh produce.
Their main reception room has huge ceilings with all of its original features such as wooden beams kept exposed.
Inside there are plenty of traditional log fireplaces and burners, and the furniture all compliments the classic design of the farmhouse.
The majority of the property's furnishings are also made from dark wood to match the original features.
Prince Charles has always been passionate about environmental issues.
The Prince of Wales yesterday addressed world leaders at the Cop26 global climate summit in Glasgow.
He said: "The Covid-19 pandemic has shown us just how devastating a global cross-border threat can be.
"Climate change and biodiversity loss are no different - in fact, they pose an even greater existential threat, to the extent that we have to put ourselves on what might be called a war-like footing."
Charles told the leaders the "eyes and hopes of the world" are on them to act fast because "time has quite literally run out".
