In Trbovlje, Slovenia, a man-made cement spire rises 360 meters (1,180 feet) into the sky. The tower is a smokestack from a decommissioned power plant—and the tallest chimney in Europe. Instead of sitting dormant, the smokestack has been converted into a multi-pitch climb. It's now the longest artificial route in the world. In October, 2020, the Slovenian climbers Janja Garnbret and Domen Škofic made the first ascent of the line.

Though plastic holds bolted to a cement wall may seem like a novelty, the climbing is no joke. Not one of the 13 pitches are easier than 7b (5.12b), and the crux pitch is 8b+ (5.14a). The crux comes at pitch 10, high on the column after the climbers have been battered by difficult moves for the nine preceding pitches. The route was designed and set by International Federation of Sport Climbing (IFSC) routesetters Katja Vidmar and Simon Margon.

Škofic and Garnbret, 26 and 21 respectively, are strong sport and competition climbers, with little to no multi-pitch experience—Škofic had climbed one multi-pitch previously, and Garnbret never had. Neither climber had any beta going into the route.

“I was a bit scared before the start,” Garnbret said. “I was afraid of falling, which can get really nasty in case of a vertical wall compared to an overhanging wall where you hang in the air. Here you can quickly hit a wall or a hold before the rope stops you. Thus, I needed to fall a few times until I finally relaxed and banished the fear.”

For their first attempt, the duo reached the summit in 12 hours. Much of the climbing is gymnastic and dynamic, akin to competition-style indoor routes. They each fell several times, though between them they sent every pitch.

“The chimney is completely different from anything I've climbed so far,” Škofic said. “It is a giant, artificial object, which I found rather mystical. I felt discomfort, strong fear of the unknown but I quickly made friends with the chimney, as the route was really beautiful and challenging. Once I started focusing on climbing, all other thoughts were gone, and I was just enjoying it.”

After four days’ rest, the team tried again. On the second attempt, the two Slovenians climbed all 13 pitches in 7 hours and 32 minutes, nearly four hours faster than their previous go. This time, they each redpointed every pitch.