Phong Nha-Ke Bang
Flora and fauna
A local bus goes from Dong Hoi to Phong Nha for 40,000. It departs at 14:00 from Nam Ly bus station. The bus back to Dong Hoi leaves Phong Nha at 8:00, so you have to either stay overnight or try to go back with one of the tour buses (they may even take you to Dong Hoi for free).
Motorbikes can be rented for about 150,000 for one way or as low as 200,000 for return. Taxis are more expensive.
Tours are available from Hue.
Tien son caves: It is 50,000 dong to see both caves and 200,000(11$) to rent a boat for up to 10 people or 240,000 for 14 people. You can share a boat with other tourist that show up. Boat is needed. Caves are exquisist.
Nuoc Mooc spring: 50,000 for ticket. Transportation can be negotiated to take you there from Phong Nha village.
There are several guest houses around.