TP Hai Phong is Vietnam 3rd largest city after HCM and Hanoi...
Hai Phong operated the northern port for Vietnam...
Do Son (beach) — about 20-23 km away from Hai Phong. Do Son is resort frequented by the Vietnamese but by few westerners; the beaches are not the greatest as silt affects the quality of the water. A visit to nearby Cat Ba is advisable if you want to swim, as the water quality is much better. Do Son sits along the ocean coast, and is filled with low-end hotels, restaurants, and karaoke bars. It has a reputation as a centre for prostitution. There is a casino (one of very few in Vietnam) at the Do Son Resort Hotel. It's worth visiting for a peaceful day or two away from the bustle of Haiphong
The Do Son hotel may not be gal-friendly...
Hai Phong has red light district and 1 of the cheapest sex in Vietnam...
http://www.sino-us.com/391/14252882887.html
http://www.vietnam-guide.com/hai-phong/nightlife.htm
https://www.talkvietnam.com/2004/08/...-coastal-town/