Its hard to understand just how large the caves that surround Phong Nha are. Hang Son Doong is wide enough that the world's largest plane could easily fly through it and is tall enough that a 40 story building would fit no problem! While it is near impossible to tour (the $3,500 USD price tag keeps it out of most of our reach), at 31 KMs long, Paradise Cave is a good replacement. It's unbelievable to think that an entire marathon can almost be run while inside of a cave! Add to all this the fact that many of the caves in the area have been found within 2 decades, it becomes clear why you should visit Phong Nha now! The town is easy to get to, has great accommodations, and low-cost food making it a perfect stop in central Vietnam.
What to do
The majority of people will come to phong Nha to tour some of the worlds largest caves but stay longer to explore some of the surrounding area or spend time with a local family. Biking through the Long Bai Valley or across the suspension bridges spanning cave feed rivers, its tough to pack up and leave this place!
It is pretty much a guarantee that when you come to Phong Nha you will check out Paradise Cave. If for some reason you miss it, (we get it, it is really expensive but that's no excuse) that is a big mistake! The longest "dry cave" in Asia, the 31+KM long cave is both stunning and massive. The entrance takes you down a dozen flights of stairs into its largest chamber. At over 72 meters tall and 150 meters wide, you instantly get lost in its size.
As it was just found 15 years ago, the introduction of proper lighting and walkways was important thus the setting is still in incredible condition. While you can only walk in about 1 KM with the regular ticket (250,000VND) it is still absolutely worth it even if you are on a really tight budget. If your budget/adventure level permits, you can go on an extra-long tour with park management that takes you about 7KMs deep!
Dark Cave, Hang Son Doong, etc.
In the National Park that surrounds Phong Nha, there are likely thousands of caves, many of them waiting to be explored. Of the ones that have been found and explored, the size has always stunned people. Hang Son Doong Cave was found just 15 years ago and is the largest cave in the world. You can even fly an Airbus A380 (the largest plane in the world) easily through it or place an entire New York City block inside including 40+ story skyscrapers! There are many companies that will take you through any number of different caves in the area. Depending on what your interest is, and how long you have, you can visit Cham villages, underground rivers, mud baths in the pitch black and maybe even spot a new species! Oxalis and Jungle Boss are the two most popular tour companies in the area.
Phong Nha Caves
Phong Nha Cave is the closest to town and is likely the busiest. It is unique as it can only be accessed by taking a longboat down the river to the entrance. The Cave is roughly 7 KM long making it one of the longest wet caves in Asia, though rivers and streams head out in all directions,- many of them underground making the system much larger. What makes this particular cave amazing is the series of inscriptions and alters from the Cham peoples. As they
have not been deciphered and the Cham have lived in the region for thousands of years, they are not sure when they date from but believe they are at least 1000 years old! Access to the cave is on large boats which can take up to 15 people. The boat entire boat costs 550,000VND and each person costs 150,00VND so split the costs with others for a cheaper journey. Getting there early in the day will likely be best as you can wait around for other people to join.
Long Bai Valley
Just outside town is one of the most popular spots to spend the day. The valley at the base of the mountainous national park feeds many of the people in the surrounding areas. The massive fields of rice, corn, peanuts, and herds of nomadic buffalo make it a very attractive area to explore. Numerous restaurants, cafes, and tourist attractions have also popped up like the Nature swing and pub with a cold beer. Our favourite spot is not far away at East Hill Coffee. This amazing spot on the top of the hill overlooks many of the farms with the national park mountains in the background. Go there for sunset and have a full roasted chicken with sticky rice. You will not be disappointed!
Unless you are with a local or have some insider info, you will likely miss this unique experience. If you head along the river towards Phong Nha Cave, you will pass a very small ferry spot. You will likely miss it unless there are locals sitting there. A small wooden boat paddled by an older woman will take you across the 70 meters to a community that is cut off from Phong Nha except for this ferry and a series of large suspension bridges up the road. She takes small donations from tourists but only food or household goods from locals. After getting to the other side of the river, biking between the tiny communities and sprawling rice fields is a highlight of Phong Nha. Eventually, you will find two suspension bridges that are just wide enough for two bikes to pass each other. The second bridge has an amazing backdrop with mountains and rice fields and was a popular spot for filming during the "Alone" music video by Alan Walker and Ava Max.