Deep underground in the countryside of Ceredigion, Wales, a group of urban explorers found a fascinating relic: a graveyard of rusted, rotting cars.

Gregory Rivolet, an IT engineer, was navigating the tough terrain when he and his group found the piles of old cars.

“,” Rivolet told Irish Mirror. “Pieces of slate were falling from above our heads.”

Though the exact location of the mine is unknown, it's near Gwynedd, which is in northwest Wales. Slate has been mined in the area for centuries, with large scale slate mining arriving in the late 1700s.

It took 65 feet of rope and four hours for Rivolet and his team to make the trek into the unassuming mine. After some research, he believes the specific mine opened 180 years ago. He has an interesting theory as to how the cars ended up at the bottom of it.

(More:)

“The road is pretty dangerous in this area, especially when wet,” Rivolet told the Telegraph. “It was probably into the nearest town.”

Rivolet estimates that all the , reports Daily Mail.

And just how did he come across the stunning mine?

(More:)

"A good friend [told] me about this place and showed me a picture," Rivolet said.

“I was intrigued and started to do some research about it and realized it was in the UK. Once I found out the location of the mine, I asked a contact of mine in the UK to guide me down there.

“The whole experience was pretty intense, but it was definitely worth the risk.”

Wales was home to the two largest slate quarries in the world, the Penrhyn Quarry near Bethesda and the Dinorwic Quarry near Llanberis, and the largest slate mine in the world,the Oakeley mine at Blaenau Ffestiniog.

MORE ON WEATHER.COM:Chatillon Belgium Car Graveyard