With new caves being discovered almost every year, the Phong Nha cave complex is ever-changing. Paradise Cave, a vast underground cathedral, is 19-miles (31-kilometers) long with stunning stalactites. A dragon boat ride through the eerie, watery world of the Phong Nha Cave is a must. Thrill-seekers love the zipline and mud bath combo at the appropriately named Dark Cave, not to mention their underground river playground.
Phong Nha-Ke Bang National Park’s 8-mile (13-kilometer) jungle trek to Hang En cave, followed by camping beside an underground river, is unforgettable. A fair distance from major cities and tourist sites, the Phong Nha Caves are a popular stop on multi-day north-to-south or south-to-north tours.
The caves can be cool, even during warmer times of year, so bring warm clothing—and a change of clothes.
There are guesthouses, restaurants, and stores in the area, if you wish to stay longer.
Unexploded ordnance from the Vietnam War still litters the park: Do not stray from the trails.
The jumping-off point for the Phong Nha Caves is Dong Hoi, 25 miles (40 kilometers) away, although it’s also possible to spend the night in Phong Nha. Dong Hoi has an airport and regular trains headed both north and south. Some tours start from Hue, although the journey can take as long as four hours, so many choose to do the Phong Nha Caves as part of a full Vietnam tour.
The optimal Phong Nha trekking season is February to May. Between September and November, flooding can leave some caves impassable, while during the dry season (February to August), some streams can dry up. The weather can be extremely cold (by tropical standards) between December and February.
Besides the caves, the Phong Nha-Ke Bang National Park itself rewards exploration. Stretches of the Ho Chi Minh Trail, which supplied the Vietnamese war effort, lie within the park. The Botanic Garden has easy self-directed trails. The Nuoc Mooc Springs Eco Trail is a natural spring with bridges, walkways, and more.