Largest polder

Of the five great polders in the old Zuider Zee, Netherlands, the largest is the Northeast Polder at 479 sq. km (185 sq. miles).Larger still would be the Markerwaard, if it is ever completed, at 60,000ha 148,250acres (603km2 231miles2). However the project has been abandoned. Work on the surrounding dyke, 106km 65miles long, began in 1957. The water area remaining after the erection of the dam (32km 20miles in length), built between 1927 and 1932, is called IJsselmeer, which is due to have a final area of 1262.6km2 4878miles2.