Ninh Binh city is the capital of the province of the same name: a small wedge-shaped province south of Hanoi, which stretches from Cuc Phuong National Park in the west to a sliver of land facing out to the Gulf of Tonkin. Built on both sides of Highway 1 and the railroad connecting Hanoi with Ho Chi Minh City, the city itself is a fairly uneventful place, but it is surrounded by a stunning landscape of lush green paddy fields and striking limestone outcrops and is the hopping off point for sights and attractions including Tam Coc and Trang An, Bich Dong, Hoa Lu, Phat Diem Cathedral, Van Long and Cuc Phuong National Park.
Many of the sights are within 12km of Ninh Binh city, and the land is flat, so they can be reasonably easily reached on a bicycle or motorbike. To really appreciate the scenery you need to get out and about, and outside of the boat trips the best way of doing that is by bicycle. Although the most direct way to most of the sights involves driving along main roads, it's possible to find routes via the backstreets, particularly between Ninh Binh City and Tam Coc and from Tam Coc to Hoa Lu. The paths take you through villages and alongside rice paddies and lakes, with the ever-present karst formations in the background. Make sure you get a good map but bear in mind this may not help you and you may need to resort to asking passers-by or using GPS.
Most hotels will provide a map and rent bicycles for a few dollars and motorbikes for around US$7. Alternatively, arrange a tour or guide from your hotel or book on a day trip or longer tour from Hanoi. The town itself isn't especially noteworthy and while there are a couple of decent places to stay, increasing numbers of travellers are choosing to base themselves in Tam Coc to be even closer to some of the main attractions of the province. This can be a good idea if you're planning on spending more time in the area than just the single night that many travellers decide to go for.