The monarch will inspect her son's efforts at Dumfries House, in North Ayrshire, for the first time tomorrow.
The mansion was crumbling before Prince Charles took it in hand.
Since then, work has been carried out to revamp the house, which was designed in the 1750s by John, Robert and James Adam.
One of the main projects has been to bring back to life its historic walled garden.
A five-acre garden, which opens to the public next month, is the centrepiece of the renovation.
Evening Times picture editor Christian Cooksey has had exclusive access to the garden for the last 18 months.
Since early 2013, he has visited the house every week to document the work, which he is making into a short film detailing the full scale of the transformation.
Christian said: "There are 11 views from different parts of the garden going through the last year and a half, with inserted shots detailing what has been going on.
"I had been looking for a long-term project to do for a while and I'd seen a TV programme about how Prince Charles had rescued Dumfries House.
"I thought it would be interesting to document the development as I live near it.
"I'm pulling everything together now and have more than 1000 images that I've collected.
"I got in touch with the palace and they were very helpful.
"I've been given unprecedented access to the site and it looks amazing now, absolutely stunning."
Dumfries House lay empty after the death of the Marchioness of Bute in 1993 and now costs £600,000 a year to run.
The facility, which Prince Charles bought in 2007, employs 55 permanent staff and 25 seasonal workers, is used as a wedding venue and its education centre is used by up to 3000 children each year.
A MAIN task this year has been to address the loss last winter of a major branch of the 300-year-old sycamore tree in the centre of the garden.
The decision was then taken to have its remaining branches carefully lopped back.
An indication of how important the tree is to the area is the level of scientific analysis involved.
An internal MRI scan was done to gauge the thickness and strength of the trunk to see how much - or how little - it could be reduced without fatally damaging it.
Elsewhere, every seedling and its planting time has been fastidiously recorded, together with temperature variations and growth levels.
Besides heritage and heirloom varieties, experi-ments are being carried out in growing unusual, endangered and exotic species from seed.
In addition to new varieties, there is a push towards bringing back traditional varieties such as rare peas that have gone out of production, simply because they are tall and don't suit modern machinery; and Sutherland kale, an old crofters' variety that has almost disappeared.
To this end there will be an increase in the number of staff, complemented with horticultural students.
And it will be their determined effort which should ensure the future of this historic house.
The Queen will also see the revamped Pewter Corridor, the Blue Dining Room and the Pink Dining Room in the house built of the 5th Earl of Dumfries.
There is also an education centre, cookery school and craft skills training site.