Cave of the Illamina Doors

The entrance to this shaft is located on Mount Budogia, in the area of the Navarre town of Isaba, in the Larra-Belagua Massif.

The Larra-Belagua Massif, a globally recognized speleological reference, has been explored for more than 100 years by speleologists from all over the world,[1]​ coordinated since 1966 by the ARSIP association.[2]​ It was in this context that, in 1979, members of the clubs from Estella, Satorrak, and Frontenac began systematically prospecting the Budogia area.[3]​ In the shaft they named BU-56, they began exploration that progressed rapidly;[4]​ by the following year they had already reached a depth of -1192 m, and reached the underground river known as Saint Georges,[5]​ a finding of great importance because the theoretical course of this river had been deduced in 1953, but until that date it had not been possible to locate it, outside of its only known point: the spring of Illamina Ziloa, in the Suletina town of Sainte-Engrâce.[6]​

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