At the bottom of an abandoned mine shaft in remote hills, Ioan Lord is shocked to see a tiny pair of boot prints next to his own in the darkness.
They look fresh, but were made 200 years ago – by child miners, the last people to set foot in the passage.
The student, 24, from Ceredigion, has made it his mission to rediscover long forgotten mines in Wales.
Their existence and whereabouts have been lost from knowledge for hundreds of years.
“It’s very much like an Indiana Jones film,” said Ioan, who has uncovered ancient objects, some dating back to the Iron Age.
“The difference is I don’t fly to these locations, I just walk to them.
“There’s over 1,000 mines in mid Wales altogether. I can only say I’ve been into 300 or 400 of them. There are hundreds that are still lost.”
Ioan, who is studying for a PhD in the social history of metal mining in south Wales at Cardiff University, is the first person in hundreds of years to access many of these sites.
He uses old maps and satellite images to track them down.
Wooden crates still packed with dynamite sticks and even graves have been among his discoveries.
It is a pastime that requires next-level commitment, though, as Ioan often spends days deep underground at a time, digging passages, or wadding through partially submerged caves.
“In school, going down abandoned mines was a bit weird to say the least,” reflected Ioan.
“I was different to others, but it was extremely rewarding because after school I’d come home, put a rucksack on, and go out to find more mines.”
What appeared to be a wooden salad spoon he found deep underground was later confirmed by academics to be the oldest complete wooden mining tool ever found in Wales.
Carbon dating put the shovel somewhere between 4BC to 87AD – around the time of Roman occupation, some 2,000 years ago.
But Ioan’s exploits are not for the faint-hearted.
Before each journey, he tells friends what time he will return to the surface.
If they do not hear from him within an hour of that time, they are under strict instructions to begin a rescue.
“What we do is only possible through experience,” said Ioan.
“It is not safe to go underground on your own, or with inexperienced people.
“The main danger with metal mines, like I explore, is having rotten timbers in the false floors you might be walking on. It can mean hundreds and hundreds of feet to drop beneath you.”
Along with the practical dangers, Ioan admits he keeps an open mind about what other things might lurk in the darkness.
“I have had some things happen underground which I can’t explain,” he said.
“Miners were always very superstitious. They believed in all sorts of mine goblins and guardians and such.”
Ioan said one of his most frightening experiences was when he was alone underground and heard another group approaching down the passageway.
“Quite often you’ll run into other explorers who have come in through another entrance,” explained Ioan.
“I heard a group of other explorers coming towards me, I could hear their footsteps but when I went around the corner, I couldn’t see anybody there.
“I shone my torch straight ahead, you could see for hundreds of feet, but there was nothing. And these footsteps, about ten of them, just walked straight past me.”
Ioan credits his passion for mines to a childhood spent without a television, where he had licence to roam and explore the countryside around his home in the Rheidol Valley near Aberystwyth.
“The mines here aren’t going to be around forever,” he explained.
“They get hardly any protection at all and many of them are bulldozed from year to year, so I’m trying to preserve and document them while I can.
“Normally when you think of a Welsh mines, you think about a south Wales and coal, but in Ceredigion we have the oldest metal mines, known anywhere on the British Isles. We have workings on the hills here that date right back to around 600BC.”
Ioan said gold and silver could once be found in the mountains, attracting the interest of early settlers and invaders, such as the Romans.
To increase awareness of this ancient labyrinth of tunnels, Ioan has taken to YouTube, with his videos attracting tens of thousands of hits.
Subscribers watch him snake down endless dark passageways – and get very excited about his discoveries.
Once, while exploring a flooded Victorian mineshaft with an underwater drone, Ioan discovered an entire tramway of intact rail carts and equipment, seemingly abandoned overnight, more than a century ago.
“There was this whole train of mine carts still parked on the rails, with wheelbarrows and tools leaning against them,” he said.
“It was like seeing the Titanic for the first time.”
Ioan is always careful not to broadcast where he finds entrances, so he can preserve the “time-capsule” within.
However, most of his 30,000 subscribers have never been to Wales, something he does not find surprising, saying about 90% were from the US.
“We have got many in New Zealand, Australia. I think the reason for that is that quite often it takes people from the outside to see the value in something.
“Many of the miners who made the tunnels in the rocks of Gibraltar came from the Aberystwyth area – most of the miners who first went out to work in places like Colorado or Pennsylvania came from here.
“This part of Wales was once world famous for its mines and for its miners. Now, nobody knows a thing about it.”