Hidden Earth 2026

North Peru 2026: 2,800 m of limestone above one of the largest resurgences in South America

45 minute Lecture|Pete Talling

Abstract

This presentation continues the story of the search for deep caves on the rim of the Amazon Basin in August-September 2026. The expedition is to a high altitude (up to 3,700 m) and unusually remote limestone plateau that is underlain by ~2,800m of limestone. It has an extremely large (up to 34 cumec) resurgence of the Rio Negro at its base, which might be the largest karst resurgence in South America. The Granada Plateau is thus one of only a handful of places worldwide that has potential for new caves that are much deeper than the currently deepest known cave. Expeditions in 2023 and 2024 demonstrated the world-class caving potential of this area, and mapped and explored what became the longest cave in Peru. This exceptionally beautiful Tragadero de la Soleded streamway was explored for 4.2 km to a depth of -325m, where a boulder choke stopped further progress. However, on the last day of the 2024 expedition a 120-m-deep surface shaft was found and descended that lies only 170m horizontally beyond this boulder choke. This Golondrinitas shaft is thus well placed to be a ‘back door’ into a continuation of the Soledad streamway (although its end may need a wee spot of plug and feathering), which may eventually drain to the huge Rio Negro resurgence that is 2,800 m lower and ~25 km away. The 2024 expedition also left a series of other ongoing smaller caves closer to camp that are well placed to reach the upstream continuation of Tragadero de la Soledad, beyond a second large boulder choke. This very large (20 m x 10 m) upstream passage in Soledad is exciting as it has gone under the mountain ridge, and the nearest source for its river is >12 km away. We have also been given new detailed coordinates for a promising surface entrance with ‘strong wind’ originally found by an archaeological expedition in 2005, located above another major river sink. It too has potential to lead to major tributaries of the Tragadero de la Soledad streamway, and provide another way into its downstream continuation. The 2024 expedition stored 1.2 km of rope and associated rigging gear on the plateau, and this equipment can now be used to push caves further in 2026. Continued support from the Ghar Parau and Mount Everest Foundations has been hugely appreciated. Come along to hear how the search for the world's deepest cave (or just surviving 3 weeks of dehydrated meals and occasional spectacle bears) now unfolds.