A massive sinkhole has been announced in Phong Nha‑Ke Bang National Park. Its oval opening of about 190 m by 140 m and depth of 120 m makes it one of the region’s largest natural depressions.

The feature was first spotted when Kevin Ditamore of the U.S. National Speleological Society noticed a dark patch on Google Earth images. Three drone surveys later pinpointed the exact location. A ground expedition in July 2025 confirmed the sinkhole’s dimensions.

In July 2025, Jungle Boss worked with U.S. National Speleological Society experts to survey the sinkhole. The team descended 120 m and recorded millions of snail shells together with monkey bones and skulls at the bottom. These remains indicate a rich, still‑active ecosystem.

Pham Hong Thai, director of the park, said the formation offers new evidence of the area’s 400‑million‑year‑old karst system, making it scientifically significant for geological and geomorphological research. Despite its size, the survey found no substantial entrance to an underground cave system. Water appears to drain through hundreds of cracks rather than a single passage.

The sinkhole’s size, recent discovery, and unique interior make it a remarkable geological find in Vietnam. It deepens our understanding of the hidden biodiversity and complex karst landscape of Phong Nha‑Ke Bang.