You would probably consider Mong Cai only at most as a stopping point during your journey from China to Ha Long Bay or from Vietnam to China. However, it is a pleasant town, and the nearby Trà Cổ Peninsula has one of northeastern Vietnam's few good beaches that can be accessed by road (without taking a ferry boat).
From Dongxing, China
If you wish to come to Viernam from Dongxing, the customary manner to do this is by walking. You may leave your car or motorbike on Chinese side for a few yuans. Then you cross the border by walking and take a motorbike taxi or similar to your destination.
See the instructions at Ha Long Bay#Get in.
- Visit the nearby Trà Cổ Peninsula, with its mostly uncrowded 15-km long beach, and a lovely Gothic church. The main tourist area on the peninsula, Trà Cổ town, with hotels and restaurants, is less than 10 km from Mong Cai; bus service is available.
As this is a border city to a richer neighbor, you can use also Chinese Renminbi here.
Plenty of hotels within several blocks from the border crossings. As of January 2017, prices start from around 250,000 dong (around $12).