The Haarsteegse Wiel is a wheel located northwest of Haarsteeg. It is almost 20 meters deep, making it the deepest wheel in the Netherlands.
The wheel was created in 1610 when the water was pushed up by an ice dam in the Maas and the dike gave way. This formed the southern basin. The northern basin was created during a second flood in 1740.
Studying the sediment in the wheel not only allowed for its age to be determined, but also identified events such as past and historically known floods. In addition, change in human activity could also be observed by elemental and isotope analysis. These included the intensification of livestock farming after 1880, the arrival of tanneries and dairies, the atomic bomb tests and the Chernobyl disaster. Pollen analysis revealed phenomena such as the agricultural crisis of 1875, the development and cessation of hemp cultivation in the 19th century, the planting of pines and poplars, the development and cessation of buckwheat cultivation, and the emergence of silage maize around 1970. Study of the fossil diatoms yielded knowledge about the development of water quality, which, partly due to the use of fertilizers, has become and still is richer in nutrients.