The Outer Silver Pit is a west-to-east valley in the bed of the North Sea. Its widest part is 125 to 175 km (75 to 105 miles) east of Flamborough Head in England. It is between the Dogger Bank and the ridge dividing the northern from the southern North Sea basins, which runs between Norfolk and Friesland.
When the sea level was lower (such as in the Ice Age) it was a lake in Doggerland, and sea-bed-penetrating sonar bathymetry has found its shorelines and courses and estuaries of rivers that ran into it from the high land of the Dogger Bank; it overflowed into a river at its west end.[1]