The "Kaser" or "Câser" is a set of small, half-timbered and plastered-brick houses from the first quarter of the 20th century, built for the lime kiln workers. They make up an old mining village for the le Rocheux mining site (zinc and lead). The houses are terraced and have cob walls. They are back-to-back houses and have an upper floor, as each house was used for two families: each family had two rooms measuring five metres by five, one to live in with an open fire, and the other to sleep in.
Le Rocheux nature reserve: On the Le Rocheux site, there used to be a mine which was at its peak between 1857 and 1880, employing up to 450 workers. It was Aristide Dethier, a Theux engineer, who carried out research around 1850 to find the ancient ore deposits from the Middle Ages. He then set up the Société du Rocheux as they found iron at a depth of thirty-six metres at that place. Shafts (150 of them) were dug to extract the iron and they also discovered zinc, lead and pyrite. The metal-bearing wealth of the concession was due to a large seam, running north-south for a distance of 3000 metres and 100 to 150 metres wide. Between Oneux and le Rocheux, it touched the surface for a distance of 1200 metres. In 1862, an international jury at the Universal Exhibition in London granted a patent and a first class medal to the Société du Rocheux et d'Oneux for the quality of its products. Clinker and ore waste accumulated on this extraordinary site and this allowed the development of special and rare flora and fauna. The Le Rocheux site offers a variety of natural environments which makes it today a nature reserve. In 1949, the calamine waste heaps at Le Rocheux were also listed as Walloon heritage. Their value was also recognised at European level since they have been included in a Natura 2000 zone.
In 1550, La Bouxherie had two forges: the big one and the little one, and Lambert Boniver had a "new" house built. The 17th century saw the family flourish with his five sons, especially Jean Boniver who rebuilt the forges, one in 1662 and the other in 1676. The Boniver family is a very old and very important Theux family of forgemasters. It provided Theux with eleven mayors. In the shade of a centuries-old tree, the forgemasters' home is made of Franchimont sandstone rubble and limestone in the Mosan style, and is the jewel of the Theux heritage. Admire the cornice decorated with corbels in the shape of acorns, the studded door, the entrance steps lined with a lateral support stone, the skylights, the chimneys, the arrangement of the mullion windows, but especially the harmonious whole in Mosan Renaissance style.