Whenever we've driven the winding bush-clad road through Karangahake Gorge, peering across a swing bridge at remains of an old quartz-crushing battery we've commented, "We must stop there sometime." And finally, in the main car park, removing our bicycles from the car, "Sometime" has finally arrived. Numerous information boards tell
Riding the rails: The Hauraki Rail Trail
Subscribe to listen
The Karangahake Gorge in it's full glory.
We opt for the rail tunnel loop and pedal a dirt track above Ohinemuri River, passing a fort-like wall, remains of where the most successful gold and silver extraction occurred. Because gold here was encrusted within base minerals, it was very difficult to extract until 1889 when a process using potassium cyanide ensured economic viability.

Cycling over another swing bridge, this one crossing above traffic on State Highway 2, takes us to the mouth of the old rail tunnel. As we enter, light and warmth is exchanged for cool darkness. Dim lights above provide just enough glow to see a short way ahead, the tight brick walls gradually curving upwards. Dark shapes sway as people walk or cycle in either direction: we hear their chatter long before we pass them.
The low light makes interesting shadows. In front, when my partner cycles directly under a lamp his shadow is squat before it stretches into a long oblong and then shrinks rapidly back into a stubby size under the next overhead light. It's a memorising shadow-show distracting me from cold, damp tunnel walls and a continuous, but slight incline.
Ahead, someone releases a haunting, wailing ghost sound that carries along the walls. Its eeriness is enough for our 7-year-old daughter to lose concentration, riding dangerously close to the guttering. Only at the tunnel's exit we notice the concern on her face; she's more spooked than we had imagined.
A steel truss bridge extends out from the tunnel. On the bridge, looking back, directly over the tunnel's exit, cars can be seen travelling over SH2. As we look over the sturdy railing down to the Ohinemuri River, rising up all around are ragged hills covered in bush. Instead of turning right and taking the designated loop track back to the car park, we decide to cycle ahead on the wide, flat gravel track that extends to Waihi, just as the mining train would have.
It's 13km to Waihi. The only others we see are cyclists with small packs glued to their backs. This ride is one component of the 82km Hauraki Rail Trail that can begin at Thames, pass through Paeroa, Karangahake Gorge, Waihi and end at Te Aroha.
The sun on our backs, we follow the track as it hugs the gentle, curving hillside on the right. Around every few corners clear water runs freely down a mossy bank, falling into a pool. It's a cloudless, windless day, peaceful and warm and I want to keep cycling.
Unfortunately, Miss 7 doesn't share the same will, her little legs pedalling little wheels tire sooner than hoped. We try to distract her for as long as possible, pointing out old mining relics and naming some regenerating native trees. There are glimpses of the river below and above it standing out from other greenery are lofty umbrella-shaped tree ferns.

We turn back and just after 3pm the sun dips behind the hill in front leaving us pedalling in flat light. Back at the steel truss bridge there's an option to compete the loop track but Miss 7 says she'll go back through the tunnel if her dad doesn't make wailing ghost sounds again. It's a much quieter quicker ride back though the tunnel on a slight decline. We leave the gorge and drive back in to sunshine on the Hauraki Plains knowing we've only seen a fraction of what the area has to offer.
Lowdown
Karangahake Gorge is on SH2, south of Paeroa.
Check out: thecoromandel.com
Take a warm layer of clothing and a torch if exploring.