A clay pit or clay pit is a quarry, whether or not filled with water. A clay pit is created by excavating clay for building material (for floors or for finishing wicker walls) or for the manufacture of bricks. Loam was also used for both yard paving and for hardening roads.
After excavation, the clay pits often remained unused, allowing special flora and fauna to settle. In the Netherlands, clay pits are mainly found in Overijssel, Gelderland, North Brabant and Limburg.