A Slovenian, or more specifically Koroska version of Bob Graham Round or the 3 Peaks challenge. A challenge that started back in 2000 as an idea among a couple of friends (Milan Savellij, Dušan Štrucl in Marjan Lačen) who pondered whether it would be possible to walk/trek/run across the peaks of Koroska region in under 24 hours, without support (apart from food and water). First finished by Alfonz Prevorčič – Fonza, The trail across the 5 peaks (Urslja Gora 1699m, Smrekovec 1577, Raduha 2062m, Govca (Oljseva) 1929m, Peca 2126m) is around 90km long with around 5500m of ascending. It starts and finishes in Crna na Koroskem and the choice of route between the peaks and the direction you take doesn't matter as long as you get to each of the peaks and touch the top.
Whoever finishes the challenge becomes a 'member of the K24 club'. However, no-one really checks whether you've actually done the route, if you had other support or if you cheated. As the founders say, the challenge is based on good old 'mountain' honesty to yourself – if you lie, you know that you've lied, if you've done it, you alone can be happy about achieving this feat. [Nevertheless, for FKT purposes you must submit verification.]
This is the 'classic', self-supported route, going counter clockwise direction across Peca first and Urslja Gora last. Not to be replaced with a slightly longer route for the K24 Ultra Trail race.
Read more about it in the official media:
https://e-koroska.si/najtezji-koroski-hribovski-izziv-k24-za-uspeh-je-najbolj-vazno-koliko-poznas-samega-sebe/
https://www.k24trail.si/
Or if you'd like to see an average runner's blog with some pictures:
https://www.peterkoraca.com/blog/2018/10/16/k24-the-slovenian-bob-graham-round-or-the-three-peaks-challenge
