Ario 24 was a two week long, 24 person expedition to the Western Massif of the Picos de Europa. Based at the Vega Ario, the expedition aimed to continue exploration of Pozu Jultayu via the newly connected Cave of the Singing Pasteur, as well as to investigate other ways into the same system potentially via Tras La Jayada, and search for ways into the gap between downstream Pozu Jultayu and the resurgence at Culiembro.

Underground camp was set up in Tapeworm Passage in Pozu Jultayu, and fixed aids from 24 years ago replaced or reinstalled to allow easy progress. A number of important leads were investigated and prioritised for the 2025 expedition. In addition, a new way on in the Cave of the Singing Pasteur was identified and exploration commenced, potentially offering a dry way to Sistema Verduellenga.

In Tras La Jayada, the 300m shaft was rebolted and resurveyed. At the bottom, a rift that had been missed by the explorers of the 1980s was pushed to new pitches that were descended and later found to be within 15m of the Holier than Thou inlet in Pozu Jultayu.

Enlargement of tight and draughting rifts was carried out in Cueva de la Rana and TR2 (Cave of the Old Men’s Dreams) in the hope of breaking into cave beyond downstream Pozu Jultayu. However, these rifts remained too tight and for too long despite significant effort.

We are extremely grateful to the Federacion de Espeleologia del Principado de Asturias (FESPA) and to the Picos de Europa National Park for granting permission for these expeditions to take place. We are also very grateful to the Ghar Parau Foundation and the European Speleological Federation (FSE) for their generous support for the trips, and to Korda’s for the equipment donation. Thanks are due to the Yorkshire Dales Guides for the space for equipment storage. Last but certainly not least, the Refugio Vega de Ario deserve particular thanks for their generosity and their hospitality that has been incredibly helpful for the expeditions over the last decade or more.

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