The trading center of the Frisians in the Netherlands, from which they controlled the old Rhine, the Vecht, and the Lek until the course of the river changed. Excavations have located an earthwork defense of this medieval site and have produced enormous quantities of occupation debris including large amounts of imported Rhenish and local pottery, wine casks from the Mainz area, Niedermendig lava Querns, and stone mortars made in eastern Belgium. There is also evidence of industrial activities like weaving, shipbuilding, bone and metalworking. Dorestad is the best-excavated and finest example of a Carolingian emporium and illustrates the scale of commerce between the imperial estates in the Rhineland and other North Sea communities.