The twin spoil heaps of Loos-en-Gohelle rise to an altitude of 186 meters, as reported by the local tourism office, making them the highest spoil heaps in Europe. However, this measurement refers to their elevation above sea level, not the vertical height from the surrounding ground. The actual elevation difference compared to the surrounding plain is about 150 meters, which is enough for the heaps to be visible from more than 40 kilometers away. The dark shale that makes up these spoil heaps creates a microclimate that is approximately 5 °C warmer than the surrounding land, according to a study published in 2012 in the Annales de la Société géologique du Nord. This is an estimate based on field observations and not a standardized measurement. While the area is commonly referred to as having two spoil heaps, there are actually five, with only two being the dominant cones visible from a distance. The mining basin that created these landforms contains more than 340 spoil heaps in total, of which 51 are within the UNESCO World Heritage site designated in 2012. The chain of spoil heaps stretches over 125 kilometers to the Belgian Borinage region. These landforms are delicate and require careful management. Visitors are encouraged to stay on marked paths, and the climb to the viewpoint on the western spoil heap takes about an hour, including the return trip. The shale cones originated from the 11/19 pit, which was closed in 1986. The number 11 refers to a metal shaft from 1920, and the 19 refers to a concrete tower from 1960. The black shale absorbs solar radiation and releases it slowly, particularly on the southern slopes, which face the sun directly. Some spoil heaps are still burning, with fumaroles—vents that release steam and gases—emerging from their interiors. In Haillicourt, the vineyard spoil heap is one of the last in the region to be burning, with temperatures reaching up to 700 °C, according to the magazine Latitudes. Despite these high temperatures, sheep graze on its summit without suffering. In a region with limestone soils and a humid climate, the heat generated by these spoil heaps attracts species typically found in much warmer areas. Viper's bugloss, molinie, and oxalis with shield leaves, as well as sticky sow thistle, are among the plants that thrive here, more commonly associated with Mediterranean regions. Insects such as the Italian cricket and the turquoise grasshopper, a cricket with blue wings, also find their way to the area. The common purslane, which usually avoids cold, spends the winter in these warm microclimates. Chardonnay vines have been producing the organic Charbonnay wine on spoil heap number 9 of Haillicourt since 2014. This spoil heap, which stands 136 meters high, is part of the 2 bis pit in Haillicourt, near Béthune. It has a steep slope of 80% and is fully exposed to the south, making it the only spoil heap in France to bear vines. The contrast with the Burgundy region, the origin of the grape variety, is striking. The project was initiated in 2011 by Olivier Pucek, born in Bruay-la-Buissière, and winemaker Henri Jammet. The number of chardonnay vines planted varies between 2,000 and 3,000 according to different sources. The wine, named "Charbonnay," has been produced since 2014. Its promoters say it is a tribute to miners and is also organic. The poor, draining shale soil forces the vines' roots to grow deep, and the heat stored by the dark debris, tempered by a breeze on the hill, supports the growth of the vines. The yield remains modest: a photo report on the grape harvest mentions 450 kg of grapes carried on human backs to the base of the spoil heap. In 2022, the estate produced nearly 1,000 bottles, which were distributed to the site's shareholders and the city rather than sold. The vines can be seen from the road, but the spoil heap itself is only accessible during organized visits.