- In the field
Expedition BU56: secret code or magic words?
A secret code for the uninitiated but magic words for cavers throughout the world! BU56, aka "Sima de las Puertas de Illamina," is one of the biggest and most beautiful caves on the planet. Located in the Budoguia Mountains of Spain's Navarre region, this cave represents one of the key links within the immense PSM network (Pierre Saint Martin, which today contains 240 explored kilometers of caves). Read the expedition report as told by Phil Bence…