Note: Do not rely on this information. It is very old.
Haarlem LakeHaarlem Lake, which was drained by an English company employed by the Government between 1839 and 1852, was formerly a lagoon connected with the Zuyder Zee. In 1836, when its area was nearly 50,000 acres, the lake overflowed, and caused much damage in Amsterdam and Leyden. From the clayey soil at the bed of the lake, "klinkers" or paving-bricks used to be made.
Click for more about Zuyder