Advanced Speleology in the Laminetako System, Lekeitio

Context The Laminetako System, located between Lekeitio and Berriatua in Bizkaia, is a complex karst network with approximately 4,800 meters of explored passages. This protected area is renowned for its well-preserved limestone formations and a continuous underground river that maintains a consistently humid environment with stable internal temperatures of 12–14°C. The nearby access point at Gizaburuaga makes it easily reachable for visitors interested in advanced caving and geological exploration.

The Experience You will join a guided expedition lasting approximately 4 hours, beginning with the preparation and fitting of certified technical gear. Descend into the cave to navigate both wide and narrow passages, using climbing techniques, crawling, and movement across rough rock surfaces. You’ll feel the constant coolness and moisture while hearing the echo of water from the underground river—an immersive sensory journey that defines this caving adventure. The expedition concludes with a return to the surface and a personalized debrief with safety and experience feedback.

For Whom This expedition is designed for experienced cavers with strong physical fitness, aged 16 and older, seeking a challenging technical and physical experience in a complex subterranean environment. It is not suitable for beginners, individuals with limited mobility, or those without appropriate clothing and footwear for wet, slippery terrain.

Local Context The Lea Artibai region, where the Laminetako System is located, features a mix of mountainous landscapes and proximity to the Basque coast, with traditional fishing villages like Lekeitio. Local culture emphasizes the preservation of these natural protected areas, which are part of the region’s geological and cultural heritage.