Geological discoveries in Phong Nha-Ke Bang National Park

Recent explorations in Vietnam’s Phong Nha-Ke Bang National Park have led to the identification of significant geological features.

In July 2025, an expedition team comprising cave experts, technical staff, and forest rangers identified a massive, oval-shaped sinkhole in the Cha Noi-Khe Gat area. The discovery was announced on October 22 by Jungle Boss Co., Ltd., in collaboration with the National Speleological Society (USA) and the Phong Nha-Ke Bang National Park Management Board. The sinkhole was first spotted by expert Kevin Ditamore via satellite imagery on Google Earth, where he noted an “unusual dark patch” in the limestone terrain.

Following three drone surveys, a 24-member team conducted a deep survey from July 23 to 29, 2025. The team traversed over 20 km of dense jungle and sharp limestone mountains under difficult conditions. The sinkhole measures approximately 120 meters deep, with an opening of roughly 190 by 140 meters that expands at the base to approximately 250 meters in length and 200 meters in width. The bottom hosts a primary ecosystem with ancient trees and significant geological traces.

In October 2026, a multi-tiered system of emerald-colored calcium lakes was discovered within Hang Thang Cave. These pools, which cover up to 500 square meters, became visible due to rainwater accumulation during the onset of the rainy season. The lakes are formed by natural calcium carbonate deposits that create tiered ridges.