It doesn't take long for visitors to Pyongyang to notice the small boats dotted along the Taedong river, mounted either with cranes or laden with aggregate-filled cargoes. The presence of these dredgers, removing sands, sediment, and shingle from the bottom of the water body, is one of the many things that set the city apart.

Working all year round – with the exception of when the river freezes in winter – men aboard these boats can be seen collecting and sorting materials from the riverbed around the clock.