Getting there & away
Mong Cai is located 360km from Hanoi. Buses to/from Hanoi (75,000d, nine hours) depart regularly in the morning. Many buses and minibuses connect Mong Cai and Hon Gai (42, 000d, five hours) between 5.30am and 4.30pm. Smart folk take the hydrofoil.
For Mong Cai to Lang Son (50,000d, five hours) there is just one bus a day at 12.30pm. Don’t miss it, as going your own way involves two changes. Much of the road is unpaved – expect plenty of dust or mud.
Mui Ngoc (883 988; Pho Hung Vuong) runs high-speed hydrofoils daily from Mong Cai to Bai Chay (US$15, three hours) in Halong City at 9am and 2pm (8am and 1pm from Halong City). From Mong Cai, shuttle vans leave the hydrofoil ticket offices for the pier at Dan Tien Port, about 15km away. Arriving in Mong Cai, the hydrofoils often berth in the middle of the open sea; don’t worry, you haven’t broken down! Low tides require a transfer by small boat.
Finally, there is also a slow ferry to Haiphong (70,000d, eight hours), departing daily at 6pm. Do the maths, it arrives at an ungodly hour.