The discovery of coal or Black Gold early in the 20th century altered the appearance and improved the wellfare of the municipalities of both Heusden and Zolder. The mine of Zolder, in use from 1923 to 1992, was the last mine still being exploited in the Benelux. Besides the shafttower, some other buildings were classified as monuments. They remain a constant reminder of the former coalmining history even in their new allocated functions. The centre for durable building (CEDUBO), being a permanent informationcentrer for ecological and durable building technology, is located in the former bathhouse.The previous administration building mainly retains its former function, be it, for different companies. A relocation for the main hoisting shaft is still pending. The former mine grounds have been reorganized as an industrial area.
The market on every second and fourth Wednesday of the month, is known as the most multicultural market in the area and is located at the new marketplace, which has been created inside the old colliery site.
The coalmine tip reaches to a height of 155 mtrs. above sealevel. In 1997 the area was purchased by the Flemish community and is classified as a flemish nature reserve. A section of which is open to the public for walks. The remainder, relies for its maintenance and upkeep, on the grazing of a sheep herd.