ENCI

ENCI (Eerste Nederlandse Cement Industrie - First Dutch Cement Industry) is a Dutch company based in Maastricht, Rotterdam and IJmuiden. Their core business activity consists of the digging of marl out of St Pietersberg, which they use to make cement. The company uses the dug-up earth to make a new hill, called d'n Observant. Furthermore, there are plans to fill parts of the quarry holes with water for the creation of a water recreation area.

A pair of Eurasian eagle-owls have been nesting at the ENCI quarry since 2001, making the quarry one of the most well-known nesting sites for the bird in Western Europe.