Can you go and return the same day?

Yes. Leave early, pick two sites, and expect a long day.

Hanoi to Ninh Binh

Ninh Binh is the easy overnight south of Hanoi. Train and road both take about two hours to the city; Tam Coc is a little farther.

Mode	Time	Notes
Train	About 2 hours	Regular trains stop at Ninh Binh. Then a taxi to Tam Coc.
Limousine or car	About 2 hours	Door to door if the car continues to your homestay.

Can you go and return the same day?: Yes. Leave early, pick two sites, and expect a long day.