If you start from Hanoi. You can go by train, province bus or limousine.
It’s about 300km from Hanoi to Vinh city and 18km to go Nam Dan.
I advise you moving by train, because it’s safaty, and you can sleep in during trip. It helps you not tired for long trip. And you should go at 22h, by a train have name NA1. This train run slow, but it will bring you Vinh city at 5 am. If you move on SE train, you will arrive son, about 3 am, it’s to early to catch bus from train station to Nam Dan. You will wait 2-3 hours until have first bus.
If you catch taxi, you will pay 200.000 VND for 18km.
This is some information may help you have good choice .
This information will be very useful for other Local Guides that might travel to Hanoi. But it will be great if you can share pictures of beautiful places in Vietnam so that other Local Guides can see the beauty of the country.
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This is my hometown. So I see in near time there are a lot people to go to there. I want to let them some tips useful. I know if I enclose some pictures, they will feel clear but I just take picture for my personal. If have any pics can public, I will do it.