Phony Nha Cave is impressive – 7,729 metres long containing 14 grottoes and a 13,969 metre underground river. But the real reason to explore this cave is to understand its role in one of the greatest wars to affect the American psyche.
After an early arrival at the Phong Nha Farmstay, we started our day with a 10 kilometre bike ride to the boats that would take us to the Phong Nha Cave. The ride was what we had been imagining in Yangshuo – peaceful cycling through farmers’ fields with cows wandering past, children high-fiving us and giving us enthusiastic hellos, and even a 10-year old herding ducks with a machete resting on his shoulder (seriously).
We also saw ponds for farm animals that are essentially water-filled craters from bombs dropped during the American war. (Yes I know you are saying “Vietnam,” but perspective is everything and that’s what the war is called here.)
We bought our tickets and shared a boat with 20-somethings from Ho Chi Minh City to access the Phong Nha Cave. Several selfies later that almost led to the boat capsizing, we rounded a corner and saw the opening to the cave.
During the war, the cave was used to store a removable pontoon bridge that provided a critical connection over the Son River. This connection was part of the Ho Chi Minh trail that supplied troops attacking American soldiers further to the south . The area around the cave was also used as a training ground, and consequently the Americans dropped thousands of bombs in the region.
Today the area is riddled with unexploded ordnance, which ironically makes its way back to the US as bombs are recycled. The gun powder is used by fishermen and rock quarries in Vietnam, and the metal is sent to Japan where it is used in car manufacturing.
During the war, the Americans knew that something was going on inside the cave. One night they used flares to light up the region to see what was taking place. Reconnaissance photos showed that during the night, components of the pontoon bridge were removed from the cave, ferried down the river and assembled. The bridge then allowed supplies to be taken across the river by trucks that had been buried during the day out of sight from American bombers.
When the Americans learned of the removable bridge, they decided to bomb the heck out of the cave.The only problem with the plan was the opening to the cave, which is fairly small. The approach for bombers was difficult, with the opening at the base of a karst mountain and anti-aircraft fire coming from the mountain tops. Several planes and men’s lives were lost trying to get a missile in the exact spot.
Eventually a missile made its mark, and photos confirmed a direct hit with smoke coming out of the cave. Little did the Americans know that “Phong Nha” means windy teeth, and they had only hit the stalagmites (large teeth) at the opening of the cave. In behind the small entrance is a much larger cave system that protected the men and supplies futher inside.
Today we had the opportunity to explore the first 1500 metres of the cave by dragon boat, with a short walk back alongside the underground river. It’s the most impressive cave we’ve been to so far, but we are definitely looking forward to the much bigger Paradise Cave tomorrow!