More than 1,800 extreme sport enthusiasts will travel to the Vipava Valley to take on one of the biggest ultra marathon challenges in the country from 4 to 7 May. The toughest runners will choose the 170-kilometre Emperor route.

There will be six competitive trails of varying lengths, all starting and finishing in Ajdovščina. At 170 kilometres, the Emperor is the longest route that takes runners across 6,400 vertical metres.

The Emperor route climbs up the southern Vipava Hills and reaches its highest altitude at the peak of Mt. Nanos at 1,260 metres above sea level. It continues on the northern side of the valley to Nova Gorica, crosses the Soča River and briefly crosses the border to Italy before returning to Ajdovščina.

The fastest runners are expected to complete the trail in around 20 hours, while the upper limit is set at 46 hours. The favourites to win the Emperor race are the Czech runner Peter Jiri in the men's category and Ester Fellhofer from Austria in the women's.

The second longest is the Centurion route, which spans over 110 kilometres and 4,500 vertical metres. Runners will also be able to race at distances of 60, 30, 15 or 10 kilometres.

The visitors more keen to taste the local cuisine will be able to join the Obelix Hike & Wine, an 11-kilometre hike between the vineyards of the Vipava Valley, tasting wine and local delicacies.

The opening ceremony will take place on 4 May. The two longest races will start on 5 May in the evening as will the shortest. The other races will begin the next day.

The event will be streamed live on social media by the Slovenian Tourist Board.

The first Ultra Trail Vipava Valley event was held in 2015, when 415 runners from five countries took part. In 2022 just under 1,400 runners applied, so in 2023 the organisers were happy to see more than 1,800 applicants, coming from 36 countries.