Enci Groeve, Maastricht, The Netherlands

First Dutch Cement Industry) is a Dutch company based in Maastricht. 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.