Hang Son Doong Cave was first discovered by a local man named Ho Khanh in 1991, but it was officially explored in 2009 by the British Cave Research Association. The expedition revealed a colossal chamber over 200 meters high, 150 meters wide, and several kilometers long — earning it recognition as the largest natural cave in the world.

The cave was formed two to five million years ago by the erosion of an underground river flowing through limestone layers. Over time, parts of the ceiling collapsed, creating vast skylights that allow sunlight to penetrate deep into the cave. This rare phenomenon enables trees and plants to grow inside, forming a hidden jungle beneath the earth.

Inside the cave lie immense stalactites, underground streams, and a surreal forest under the skylights. Visitors describe the experience as stepping into another world. The journey to reach the cave requires several hours of jungle trekking, river crossings, and climbing through rugged terrain before reaching the main entrance.

Access to Hang Sơn Đoòng is strictly regulated. Only authorized expedition tours are allowed under national park supervision. Participants must be physically fit, pre-qualified, and book months in advance. Each tour admits a limited number of visitors to ensure conservation of the cave’s delicate ecosystem — a true model of sustainable tourism.

By 2025, Hang Sơn Đoòng remains a global symbol of adventure and natural wonder. Travelers from around the world continue to journey to central Vietnam to witness its majesty. The surrounding communities benefit economically and environmentally through eco-tourism, making Hang Sơn Đoòng an enduring example of responsible exploration.

• From Hanoi, you can take a flight or train to Dong Hoi City, then continue by car for about one hour to Phong Nha–Ke Bang National Park. From there, you can join an authorized tour that includes hiking and an overnight stay inside the caves.

• Good physical fitness is required; prior trekking experience recommended

• Book at least 6 months in advance

• Bring waterproof gear, flashlight, and sturdy hiking boots

• Entry without an authorized guide is prohibited

• Best season to visit: February – August

Admission Fee

• Vietnamese visitors: Approximately 55,000,000 – 60,000,000 VND per person

• Foreign visitors: Approximately 70,000,000 – 75,000,000 VND per person

The price includes trekking, professional guides, meals, and cave accommodation for a 4-day, 3-night expedition.

Opening Hours

• Open only during the dry season, approximately from February to August each year. Visitation is organized in limited expedition tours with small groups under special permits only.