Just outside Vienna, climbers scramble up "Fortress Europe", one of the routes up an impressive rockface towering over fields and forests.
But the name -- and others like it that some climbers see as racist or sexist dog whistles -- is raising hackles in Austria and elsewhere.
"The usage of these names leads to a normalisation of right-wing extremist propaganda that is simply spread," climber Daniel Kufner told AFP as he set out with a friend to scale the route.
By age-old convention, whoever first climbs a route up a rock gets to name it.
Kufner and others blame one avid Austrian climber in particular for the tension over names in the small Alpine nation.
Thomas Behm has pioneered many hundreds of routes there and published several guidebooks.
They accuse him of waging a persistent campaign to spread far-right ideology through route names.
As well as "Fortress Europe", they include "Greta Dummberg", a play on words labelling the teenage climate change activist Thunberg as "dumb", and names of traditional desserts now regarded as racist.
- Nazi terms -
Others contain thinly-veiled references to Nazi terminology, according to historians, which strike a particular chord in Austria, where Adolf Hitler was born and which his Nazi Germany subsequently annexed in 1938.
With anti-Semitism well documented in the past in climbing circles both in Austria and Germany, several outlets have distanced themselves from Behm's books. And the Austrian Alpine Club no longer sells them.
"The Alpine Club deals with its mistakes of the interwar period carefully and responsibly," it said.
Behm told AFP that he didn't want to talk about the route names. "In my view, this topic has already been sufficiently dealt with."
But in an article last year, he accused "hysterical counter-movements" of questioning names that "look at climate change and its protagonists ironically, or terms that address the dogma of excessive political correctness."
However, Behm has changed some of his route names or dropped them altogether from his latest guidebook.
The "Greta Dummberg" route is now called "Greta Thunfisch" (Greta Tunafish), and "Fortress Europe" was flippantly abbreviated to "FEurope".
- 'Zyklon' and 'Little Hitler' -
The debate over controversial route names extends beyond Austria's borders.
In Sweden, more than a dozen Nazi-associated names, such as "A Little Hitler", "3rd Reich" and "Zyklon", have appeared on climbing spots near Stockholm, causing indignation.
"Many climbers understand the criticism, but at the same time think that you... shouldn't try to censor or block an old tradition," Andreas Andersson, head of the Stockholm Climbing Federation, told AFP.
In the United States, California-based group Climb the Gap, which aims to encourage climbers of colour, has compiled a spreadsheet of hundreds of controversial names since the Black Lives Matter movement began in 2020.
They got some climbers and publishers to change offensive names, and lobbied advertisers, according to group founder Jaylene Benggon Chung.
"I think people have become more aware of it," she said.
"There are of course very loud voices of people who are defensive and don't think anything needs to change, but for the most part people understand why it's inappropriate," the activist added.
Kufner said he was "absolutely in favour of climbing remaining as free as it is" and that changing the names "must be agreed among ourselves".
At a campsite near the "Fortress Europe" route, opinions differed on how to deal with the problem.
One climber from Prague said it was right for the first person up a route to choose whatever name they liked. But another from Hungary said name changes should be considered.
Meanwhile, a plaque that appeared one day commemorating "all those who have died due to the Fortress Europe" was quickly torn down.