The Cumbre Vieja Ultra Trail joins the Reventón line-up in 2023 and also becomes the venue for the Spanish Absolute Ultra Trail Running Championship. A spectacular event in which a maximum of 100 runners will take part, completing 70.5 kilometres and more than 8,100 metres of cumulative elevation gain.

The first half of the race follows the exact course of the marathon and from the Refugio del Pilar, it turns southwards, crossing a natural volcanic barrier that reaches its highest point in the Las Deseadas area. It then descends towards the west in the direction of Las Manchas neighbourhood, where the image that the athletes will encounter changes completely, to once again begin to ascend through a volcanic area and then link up with the route for the Marathon and Classic modalities. With a completely volcanic area that runs along the Route of the Volcanoes and descends to pass very close to the new volcano, the Cumbre Vieja Ultra Trail will leave a unique landscape in the retina of its runners.

A maximum of 100 bib numbers will be allocated in strict order of registration. In order to participate in this modality, previous experience is required: it is compulsory to provide documentary proof of having completed a competitive foot race of at least 30 kilometres in the twelve months prior to the event. In the event of not being able to comply with this requirement, the Reventón Trail El Paso regulations also contemplate the possibility of substituting this requirement with a stress test certified by a registered medical professional in the three months prior to the race.