Phong Nha was quite a trip. A ten hour overnight bus ride from Hanoi (dropping us in town at 4AM -- oof!) it's famous for its beautiful caves. Nearby is the recently-discovered world's largest cave, which has a waiting list and 3000 USD price tag to get in! We stayed for two nights, did a bunch of relaxing by the pool, motor biked around the area, and visited two caves.
First we went to Phong Nha cave, which you enter by boat. It's so magical inside -- it immediately goes dark and cool, and the boat engine shuts off as the driver paddles us through silently. It's cavernous and stunning , lit by electric lights in all the right places. We had such a good afternoon there!
The next day we motor biked to Dark Cave, well-known for its adventurous offerings. We zip lined over a river to get to it, then swam to the entrance, then trekked in. This one isn't lit at all (hence the name) and so we had helmets with head lamps. As we went deeper and deeper into the cave, the mud started! Eventually we came to an insane mud pit, where the mud is so thick that you can lift up your legs and be suspended where you are. It was wild. After we were fully covered in the mousse-like mud, we made our way back out, even at one point slithering on our bellies to make it through the crevices (that part I did not like). Once out, we kayaked, then swam, then zip lined right into the river. It was certainly an experience we'll never forget!
The adventure continued the rest of the day, as we motor biked through the jungle and lost an exhaust pipe. Breaking down on the side of a windy road in the jungle without phone service is quite unnerving! But after some time we were fine and got food in our bellies and watched the sun set over the river.
So glad we made this stop in Vietnam before heading south!