We took an overnight train from Hanoi to Dong Hoi where we stopped for a quick breakfast then headed to the Phong Nha Caves. To get there though you had to ride a river boat about 45 minutes (40 km) to get there. Along the way you could see small villages, an orphanage and even a church on the river’s edge.
We were a little bummed we couldn’t ride the boat into the cavern because of the high water flow, but we walked up to the second cave called Tien Son. There were a ton of very steep stairs to get there, but it was completely worth it. The caves were huge. The rock formations inside were comprised of limestone.