Pro mountain bikers Jono Jones and Olly Wilkins shared a crazy video of biking through an abandoned lead mine in Slovenia. While the Peca Mine in Meลพica offers more tame experiences for visitors, adrenaline junkies flock here for the underground Black Hole Trail. Here’s how Jones and Wilkins’ guide Mountain Bike Nomad describes the trail on their website:

“Black Hole Trail is a mountain bike trail through abandoned tunnels of Lead and Zink Mine Meลพica. Before the trail was built, a human has not set foot in these tunnels in over 25 years. The colossal chambers used to hold tonnes of lead which was mined in the past. The trail runs over five levels of the mine and descends a total of about 150 metres.”

If you are claustrophobic, this video is not for you. Check out the white-knuckle inducing footage below:

Photos and Video Courtesy of Jono Jones and Mountain Bike Nomad