In summer, its leaves absorb the light; warming, ripening, synthesising the star's vital energy before it fades behind the mountain early in the afternoon. This celestial/terrestrial movement has been played for some 140 years. A daily, seasonal cycle. From above, looking west towards the Brokenback, you can clearly see the caramel-red and ancient ochre colours of one of the most significant vineyards in the Hunter Valley. Old Hill. First planted in 1880, it's one of the oldest commercial vineyards, not just in the Hunter Valley, or in Australia, but the world.

"There are ghosts up there, mate," says Phil Ryan, who made wine from the Old Hill for 35 years, for Mount Pleasant. "You're going back well over 100 years now, and the people that put all this together - King, O'Shea, Don McWilliam and Brian Walsh - they're all still up there."

In 1880 Charles King, eponymous son of a learned farmer from Oxfordshire in England, planted a vineyard of shiraz and other assorted wine grape varieties, north to south, along the contoured slope of a steep hill at the foot of Mount Bright. King didn't know it, of course, but this young vineyard which he'd just planted would become the cornerstone for some of Australia's most legendary wines.

"I get goose-bumps whenever I walk up there," Ryan remarks. "There's footsteps in the ground of those who've gone before you. For over 100 years, people have been walking up to the vines on that hill. You can feel it. And it's a very important place, in terms of wine and the Hunter."

Day after day, year after year, season after season, the great old grape vines of the Old Hill endured. Growing, silently and patiently, waiting their turn, each and every year at vintage time - ever since 1880 - to surrender their annual liquid memoir of this place.

"There's a definite air about the Old Hill," says Graham Doran, ex-Mount Pleasant viticulturist.

Doran nurtured the vines of the Old Hill for 20 years. He was the first full-time viticulturist ever hired by McWilliams to manage all the vineyards of the Mount Pleasant estate.

"When I was appointed at Mount Pleasant and first saw the Old Hill, I called it the Geriatric Ward," says Doran. "The block had severe soil erosion to the point where some of the old end posts at the bottom of the hill had only their tops showing, with the rest covered in dirt. However, there was no doubting the quality of the fruit that came from that site. The challenge for me was to restore the vineyard and bring its management practices up to date."

Old Hill rises gently from its base at the bottom of a gully, ascending slowly, almost in parallel with the contours of Mount Bright behind it. Its caramel-coloured topsoils are comprised of a light red to yellowish tinted clay loam overlying permeable clay with highly weathered sandstone and traces of limestone underneath.

A soil survey in 2000, performed by soil scientist Dr Geoff Kew with Graham Doran, found that the roots of some of the oldest shiraz vines penetrated up to two metres down through fissures and rifts in the rocky subsoil.

"Obviously, the vines weren't irrigated until the PID was connected (in 2000), so, for a long time, they would have had to find their own source of water by extracting soil moisture from the rock," Doran explains.

The vine rows of the Old Hill run north-south, and face east towards the coast. This is significant for two reasons. First, the cooler rays of the early morning sun shine onto the grapevines through the fresh air of the morning, gently awakening them to begin their task of ripening fruit. Second, being planted on the foothills of Mount Bright, the vines are spared the intense heat of the afternoon as the mountain shades the site earlier in the day, ensuring the vines can rest and recover faster.

"When the sun comes up, the sun's rays have to penetrate more atmosphere and there's less UV light getting through," Doran explains. "So, early morning sunlight is the most beneficial for the grapevines, because they're fresh and ready to take in nutrients, and get on with photosynthesis. Then, as the day wears on and the sun rises higher in the sky, the vines heat up and ripen the grapes. If it gets too hot, the vines will shut down and stop ripening."

Excessive heat can be a problem at many other vineyard sites throughout the valley. Not on the Old Hill, though. Here, the early shade granted by the steep rise of the mountain behind it means it rarely ever gets too hot for the Old Hill vines to stop functioning.

"That earlier shade cools the site quicker in the afternoon, giving the vines a chance for better acid retention in the fruit," says current Mount Pleasant winemaker Adrian Sparks, clarifying Doran's initial explanation.

"When the fruit holds its acids better it gives you a fresher tasting wine. I can't explain why King chose this site, but he must have known something about planting a vineyard judging by just how right he got it."

Adrian Sparks is only the fifth Mount Pleasant winemaker in almost a century, since the Mount Pleasant label was established in 1921 by Maurice O'Shea.

Sparks follows in the footsteps of some Hunter Valley winemaking legends, including Brian Walsh, Phil Ryan and, of course, the man who started it all, O'Shea.

"It's amazing to think that the Old Hill was already 41 years old when O'Shea first came here and started making wine," remarks Sparks.

"It would have been the basis for all of the reds he ever made. It's the one block that beats the heat, beats the rain, and anything else Mother Nature throws at it. It's an incredible vineyard that just keeps on keeping on."

In 2013, Jim Chatto was the fourth Mount Pleasant winemaker to follow O'Shea, Walsh and Ryan up this great hill to make wine off the old centurion site. His contribution to the Old Hill story was to recommence bottling the site as a single vineyard wine, made from 100 per cent shiraz, which today is called 1880 Vines Old Hill Vineyard.

"The Old Hill was the one site whose fruit always looked really good every single year," says Chatto.

"Each vintage you'd think 'wow, there's something quite significant about that vineyard' ... It just smells and tastes so different to any of the other sites at Mount Pleasant. There's this high-toned black fruit expression that you just don't see in any of the other Mount Pleasant vineyards.

"The tannins always stand out for me too. They're a really fine tannin. And the colour is always so intense. You can see it as soon as you put it through the crusher, just by looking at the colour, that the fruit is from Old Hill."

Rare as they are, there are still a few old bottles of Mount Pleasant wine in existence, which were made by O'Shea himself from fruit harvested off the Old Hill. Those privileged enough to taste them swear of their breath-taking brilliance, energy and longevity. However, throughout the years, much of the greatness demonstrated by this old Pokolbin hill of humility was, really, only ever known to a select few who had the privilege of opening some of these rarefied bottles. Otherwise, you would have had to work directly with the Old Hill site itself.

"It was the best wine, every year," proclaims Graham Doran. "Some years were better than others, but every year it's the best. The colour of the juice is just so intense. I can remember picking the fruit and looking at my hands and thinking I'd cut them or something. Oh, they'd be blood red! That's how intense the colour of that fruit is."

In fact, the fruit from the Old Hill vineyard was revered so much that winemaker Phil Ryan would reserve an entire nine-tonne fermenter, especially. Nine tonnes of precious vacant space during vintage was kept empty until all the Old Hill shiraz was picked and brought safely into the winery at the bottom of the hill.

"I can remember, there'd be bloody grapes coming in from everywhere, from all around the Hunter, and the fermenters used to fill up quick. But there was always one nine-tonne fermenter left waiting for the Old Hill. People would ask, 'well, what about that one?', and Phil would say, 'go near that and I'll kill you. That's reserved," Doran recalls laughing.

The Old Hill vineyard is one of a handful of exceptional sites that holds a special place in the history of high quality wine growing in the Hunter Valley; a region mostly revered for its world-class white wines of semillon and chardonnay. Thus, the fact that it's such a special site for red wine, rather than white, situates the Old Hill vineyard in exalted and rather uncommon company.

"There's been some great people working at Mount Pleasant over the years; people who've had all manner of awards and accolades bestowed upon them," says Phil Ryan, who, himself, is recognised as a Hunter Valley Living Legend. "But it's not really you. It's the vineyard."

A vineyard that is fundamentally responsible for some of the most profound wines ever made, anywhere in the world, by one of Australia's most revered and first-ever great winemakers.

"That vineyard has already outlived King, and O'Shea, and Brian (Walsh), and it'll outlive me and you and everyone else ... It's always the vineyard that's giving you the recognition," Ryan continues.

"All you're doing is taking a great resource, which the vineyard gives you, and turning it into wine. But, you can never truly create a great wine. You can only ever try to transfer that greatness from the grapes into wine."

The Old Hill vineyard is a true Hunter Valley kingmaker, where greatness endures and glory is bestowed upon its winemakers and their wines.