Nampo is a working port city; expectations should be set accordingly. The West Sea Barrage at the mouth of the Taedong River is the single sight that justifies the half-day trip from Pyongyang. Tour itineraries also sometimes include a visit to a cooperative farm in the rural hinterland, the Nampo Stadium (occasionally used for staged mass events), and the hot springs at nearby Onchon if the guide is in a generous mood.
You will not wander Nampo on your own. The city is shown to foreign visitors only on guided tours, and the routes are tightly choreographed. Bring a notebook and observe.