It's not Hai Duong province. It's Bac Giang province. Exactly it's Luc Ngan district.
If you wanna have a wonderful experience, if you wanna see the vast litchi hills, if you wanna pick up the litchi on your own ,if you wanna see the roads which are full of litchi or something like that, welcome to Luc Ngan. Definitely you will have great time