The Keersop is a small stream located in the Noord-Brabant province of the Netherlands, flowing as a tributary within the broader Dommel river system. This intimate waterway is notable for its ecological significance, particularly as a stronghold for rare and sensitive species that depend on clean, well-oxygenated water and undisturbed sandy and silty substrates. The stream has been the focus of considerable conservation attention, making it a unique destination where anglers can experience fishing in a carefully managed natural environment. Its connection to the Dommel downstream means the Keersop functions as part of a larger interconnected watershed, and fish and lamprey populations move between these reaches seasonally.