The Eerste Nederlandse Cement Industrie (First Dutch Cement Industry), or ENCI, was the leading Dutch cement producer. ENCI was founded in 1926. The first kiln in Maastricht was lit in 1928. ENCI closed in Maastricht in 2020. Twenty-three buildings on the ENCI site are designated as historic monuments. Some of them can be viewed for the first time with a guided tour on Open Monument Days in September 2025 How did ENCI make cement? The main raw material for cement production is limestone. In Maastricht, marl was used as limestone. This marl came from the Sint-Pietersberg quarry. First, the large chunks of marl were crushed. These smaller chunks were sieved and dried in a limestone dryer. Then, the marl was ground into a powder in a flour mill. The powder was then heated to around 1,450 degrees Celsius. This triggered chemical reactions. The fine powder thus turned into clinker. This is a semi-finished product consisting of small, dark gray balls. These were ground into powder in large ball mills along with other raw materials. This powder is the cement as we know it.

ENCI quarry The ENCI quarry is a wonderful example of how an industrial area has been reclaimed. Since 1926, limestone has been mined in the ENCI quarry to be used in the nearby factories for cement production. This created a huge hollow in the landscape, causing older underground marl quarries to disappear. While excavating the seventy-million-year-old limestone, primarily formed during the Maastrichtian period, ENCI employees uncovered remarkable fossils. Because the chalk layers formed in a shallow subtropical sea, these were primarily the remains of marine animals such as sea urchins and shark teeth. The Mosasaurus, also known as a lizard, also swam here. Several bones from this creature, one of the last species from the age of the dinosaurs, have been recovered. You can admire them in the Natural History Museum in Maastricht (de Bosquetplein 7). The ENCI, the First Dutch Cement Industry, was of national importance. For ninety years, it was a major supplier of limestone for cement production. In addition to lime extraction, the semi-finished product "clinker" and the final product, cement, were also made. The last lime was only extracted in 2018. After that, the quarry was redeveloped into a nature reserve thanks to Natuurmonumenten (Dutch Society for Nature Conservation). Now, from a spectacular vantage point, you can enjoy views of the Meuse Valley, the quarry, and the surrounding forests. You descend into the quarry via 215 steps, past the various chalk layers, back in time. Ultimately, you walk across the former bed of the Chalk Sea. Opening Hours The walking path through the quarry is open daily from April to September 1st, from 8:00 AM to 8:00 PM. From September 1st to April 1st, the quarry is open from 9:00 AM to 5:00 PM. Visitors can enter the quarry on foot from both sides: from the steps at the end of Luikerweg 80 and from Chalet d’n Observant (Lage Kanaaldijk past number 117). Due to the height differences, the quarry is not accessible for people with disabilities. Dogs are not allowed in the quarry. Source: www.visitmaastricht.nl (Tourist Office)

Luikerweg 80; steps and panoramic view

Luikerweg 80 is also the start (or finish) of the long-distance hiking trail "Pieterpad", which leads from the far north of the Netherlands (from the village of Pieterburen), to the far south of our country: Sint Pietersberg. The total distance of the trail is over 500 km (around 311 miles). The route is divided into 26 stages that you can walk in either direction. We encountered people there, drinking champagne to celebrate completing the entire route in 26 days!!

Eagle owls in the valley

The last lime was only extracted in 2018. After that, the quarry was redeveloped into a nature reserve thanks to Natuurmonumenten (Dutch Society for Nature Conservation). Now, from a spectacular vantage point, you can enjoy views of the Meuse Valley, the quarry, and the surrounding forests. There are marked hiking trails through the quarry ranging from 3 to 5 km in length. It is very interesting that a pair of eagle owls has settled here. For more details about the eagle owls in the quarry valley, click HERE.