The closest attraction to Ninh Binh is Tam Coc, a network of three beautiful caves carved by the local river as it winds through the karsts. Surrounded by paddy fields and dwarfed by the karsts towering above, a row down this river is a serene, peaceful experience that allows you to take in the natural beauty of the area at a gentle pace.
There are almost 2,000 low income families in the area who take turns to row boats up the river, spending the rest of their time working in the paddy fields. Obviously this means their chance to row may only come up once every week or two, and since the cost of a river trip is just a couple of dollars most try to top up their row-boat income by selling handicrafts, embroidery and T-shirts on the boats.
If you would prefer to relax and take in the scenery rather than spend your boat ride haggling consider offering a generous tip or making a token purchase - the boat ride is already fantastic value and people living in the area depend on the additional income from tourists.