For cave enthusiasts seeking truly unique and extraordinary geological formations, the Hang Va and Nuoc Nut Cave expedition offers an unparalleled adventure within the Phong Nha-Ke Bang National Park. Often explored together on physically demanding tours (typically 2 days/1 night), these caves are less about colossal size and more about the incredibly rare and fascinating calcite formations found within, particularly in Hang Va. Access requires trekking through jungle terrain and navigating cave passages, demanding good fitness and an adventurous spirit.

The journey typically involves trekking through varied landscapes within the park's core zone before reaching the entrances to Nuoc Nut and Hang Va caves. Exploration involves wading and sometimes swimming through underground rivers, navigating rocky terrain, and potentially using safety harnesses for certain sections. The absolute highlight is encountering the astonishing array of rare calcite formations inside Hang Va, including hundreds of striking, conical stalagmites rising from terraced pools – a geological spectacle found almost nowhere else on Earth in such density.

Like Hang En and Tu Lan, accessing Hang Va and Nuoc Nut requires booking a specialized adventure tour with a licensed operator (such as Oxalis Adventure, which manages tours to these specific caves as of April 2025) due to their location and the technical aspects of exploration. This expedition is geared towards experienced trekkers and cave explorers fascinated by unique geology. It offers a challenging, rewarding, and scientifically significant adventure deep within the heart of Phong Nha's UNESCO World Heritage landscape.