Jim Eagles stops for a good look at a beautiful spot he's passed by hundreds of times before on State Highway 2 — and wonders why it took him so long.
Phil Mulhern's enthusiasm is not the least bit dampened by the failure of his experiment with a $2 plastic raincape small enough to fit in his pocket.
As the rain gets heavier - and water trickles down his neck - he continues to expound passionately about the glorious bush, the magnificent stone cliffs, the rampaging river and especially the intriguing tunnels, huge old machines and fascinating stories left behind by the great age of gold.
With a wave of a damp arm he indicates where a steep, tree-covered, rocky hillside, just across the river from us, once housed an enormous processing complex built to extract gold from quartz dug out of the Crown Mine.
It seems improbable a factory could be built there but Phil has the photos to prove it. And if you look carefully through the mist you can indeed spot mysterious openings in the hillside, tumbled concrete foundations and the rusting remains of a giant chimney which confirm that something big stood there a century ago.
This is the Karangahake Gorge, between Paeroa and Waihi on SH2, less than two hours' drive from Auckland or Hamilton.
I've driven through there hundreds of times over the years, always on the way to somewhere else, and many a time I've looked at the scenery or the walkers on the riverside track, and said, "We really must stop off here some time." Now I wish I'd stopped sooner.
The gorge has been shaped by three powerful forces: the geological pressures which eons ago created a rugged, rocky landscape; high rainfall - 1200mm a year - which is still feeding turbulent rivers, carving deep gorges and watering verdant forests; and rich veins of gold, whose lure has seen towns spring up overnight and vanish as suddenly; vast networks of tunnels carved into seemingly impervious mountains and networks of tracks cut through inhospitable terrain.
It's one of those tracks we're walking now, a spectacular, winding route along the Waitewheta River, originally carved out of the bank for a horse-drawn tramway used to carry quartz from the mines to the processing plants.
You don't need a guide to enjoy such places but Phil, who has turned a lifelong interest in the area's history into a business, Beach, Bush and Heritage Walks, is a mine of information (pun intended) which definitely adds to the experience.
Our walk starts at Dickey Flat. So who was Mr Dickey?
"Actually," says Phil, "it wasn't Mr Dickey. Dickey was a horse. The horses that used to draw the trams were brought here to rest and then taken back to the mines. But in the morning they'd often find Dickey had escaped. And when they went looking he'd be back here enjoying the grass. So they named the area after him."
There are little nuggets of information like this round every corner.
At the end of a point jutting into the river Phil points out a tunnel cut through the rock to act as the intake for a wooden raceway which carried water along the bank to a plant downstream.
Hidden in the bush up a slippery rock staircase he leads us to some huge rusting stampers - so called because they were used to stamp on the quartz to crush it and free the gold - left behind when the plant was abandoned.
Across a swingbridge and through a series of small tunnels his torch lights up the extraordinary Woodstock Pumphouse, a huge cave carved into the mountain, inside which the remnants of the enormous pumps stand in the gloom like so many paralysed giants.
In a cliff-face alongside the track he draws attention to some smaller veins of the gold-bearing quartz it was all about. High up in the cliff opposite are the windows cut in a mine tunnel to let in light and air. The walk through the windows tunnel is closed for the moment while a new passage is cut to link it up with the river-bank track and create a loop walk.
And when we reach the end of the track at the sleepy little settlement which is Karangahake today, Phil has countless stories - and old photos to illustrate them - about rumbustious goings on in the days when it was home to 2000 people.
With so much fascinating information, a walk which you could probably do in a little over an hour takes more like three. And there are plenty of other great tracks in the gorge area, mostly along the river banks and all taking in historic mining sites, beautiful waterfalls and old tunnels.
Probably the most interesting of those historic sites is the Victoria Battery, a century ago the largest quartz-crushing plant in Australasia, and for a time the richest goldmining operation in the world.
The plant closed in 1954 and most of the equipment was moved away but the endless rows of concrete foundations spreading out along the river plain show what a vast enterprise it once was.
That impression is confirmed if you visit the old powerhouse building where a small band of enthusiastic volunteers have created a great collection of mining equipment, photos and other artefacts of bygone times.
There were 200 stampers, pounding away 24 hours a day, six days a week, smashing 800 tonnes of quartz a day.
"The noise must have been incredible," says Max Moffat, one of the heroes who keeps the place going. "Apparently it was still loud enough to be heard in Waihi [5km away] and even in Paeroa [12km away on the other side of the gorge]."
To prove the point he operates a miniature stamper, a quarter the size of the real ones, which crushes quartz with a sharp bang. Goodness knows what the sound of 200 full-sized stampers was like.
Max and his colleagues run tours of the site, carrying visitors round a 1.5km long diesel-powered mining tramway system. You can also climb up the hill above to see eight huge bricklined kilns in which, for a few years, the quartz was stacked on layers of firewood and cooked to make it easier to remove the gold and silver.
Just across the Ohinemuri River from the museum is a further wonderful reminder of times past, the Goldfields Railway, a remnant of the defunct east coast line.
Another group of enthusiastic volunteers has preserved the stretch of track from Waikino to Waihi and runs a regular round trip for visitors.
Unfortunately their steam engine is in need of repairs, but even with diesel power it's a delightful trip, sometimes on the riverbank, other times alongside the highway with motorists and truckies sending friendly toots and waves of greeting.
"This is living out a dream," says the driver, Ron Wilton. "I wanted to be an engine driver but my Dad said I had to take over the family dairy farm. Now I've retired I'm finally able to do what I wanted. It's great fun."
If all that history makes you hungry, the good news is there are plenty of good places to eat ... and each one has a story.
The base for the railway, for instance, is the Waikino Station Cafe which serves good, wholesome food and has some great displays on the history of the railway.
"This isn't actually the original station," explains proprietor Karen Morrow.
"That was about the size of a bus shelter. This was the Paeroa Station but it was moved here when the line closed."
Not far away above the lovely Owharoa Falls - another of the gorge's little secrets - is Goose Farm which has a cottage for rent and tearooms where you can enjoy a rich, decadent, Devonshire tea.
But hang on, where are the geese?
"We used to have a goose called Henry," says owner Rick Davis, "but he got old and grumpy and used to attack people. Every morning Henry used to waddle up to our bed-and-breakfast cottage to admire himself in the glass door and our guests were scared to come out. So he had to go."
At the other end of the gorge in Karangahake itself is Ohinemuri Estate Winery which, as well as making a range of interesting wines, has a delightful cafe and a self-contained flat for tourists.
I've often seen the winery sign while driving past and thought it a strange place to make wine. Proprietor Horst Hillerich, who trained as a winemaker in his native Germany, says,
"We thought we could grow grapes here. The first year was quite dry and we even planted some. Then we discovered it usually rains 1200mm a year. Now we buy our grapes in from Gisborne and Hawkes Bay."
So why stay?
"The tranquillity. The beauty. It's like nowhere else I've ever found."
What to do: Beach Bush and Heritage Walks can be reached on 0508 924 448.
Information about the network of Karangahake Gorge tracks is on the Department of Conservation's website, at the Paeroa and Waihi Information Centres, the Waikino Station Cafe or the Karangahake Reserve.