Lezennes quarries

The quarries of Lezennes constitute a group of underground passages of about 250ha (it would be in reality 400ha). They are located south of Lille and go from Hellemmes to Lose and have several advantages: near Lille, the chalk used since the 12th century is not very deep, so they are relatively easy to exploit. Today, there are many collapses and embankments due to the constructions made on the surface, making the quarries disappear little by little .
==Chronology==
===5th Century B.C===
The Gauls begin open-cast chalk mining.
===843===
Treaty of Verdun: the frank kingdom is divided in three parts. The region of Lezennes is part of Charles the Bald's kingdom. Charles the Bald divides his kingdom into regions: birth of the County of Flanders.
===1136===
The name Lezennes appears for the first time.
===1461===
First document which proves that the chalk of lezennes is extracted for the construction of the Rihour palace in lille .
===1606-1635===
Economic prosperity, construction of numerous sites in lezennes stone.
===1769===
Treaty of the Limits which definitively attaches Lezennes to France.
===1791-1793===
The persecuted clergy during the French revolution hid animals and food in the quarries and celebrated clandestine masses there.
===1851===
Start of mushroom and capuchin beard cultivation.
===1985===
Teenagers get lost, condemnation of the entrances to the underground.
==Utilization==
The quarries of Lezennes have been used for various activities. From the beginning of their existence in the Middle Ages to the present day, there have been many developments.
===Chalk===
The extraction of chalk may have begun before the Middle Ages, as early as the Gallo-Roman period. The Gallic tribes present on the territory probably used it for agriculture. The first to extract chalk for use as a building material were the Romans, whose buildings have been found around the SNCF workshop in Hellemmes.
However, it is only in the 15th century that the site of Lezennes realized its full development. It was the Duke of Burgundy Philippe le Bon who made Lille one of his main cities. He decided to build the Rihour Palace (located on the actual Rihour square) in order to welcome foreign delegations, ambassadors and to allow the organisation of ceremonies. It was not until 1527 that brick and chalk were used for housing, due to the fires facilitated by wooden buildings. In the 17th century, the Lezennes quarry reached its peak, notably with the construction of the Citadel ordered by Louis XIV and built by Vauban. Then, little by little, its exploitation decreased, notably because of the siege of Lille in 1792 by the Austrian army . Then, more and more frequent collapses, especially under roads, forced the authorities to issue several regulations. In addition, new "industrial" quarries opened in Wattignies, Ronchin, Faches-Thumesnil etc. Chalk ceased to be mined at the end of the 19th century .
===Mushroom and "capuchin beard" cultivation===
The quarries are the ideal place for the exploitation of these two plants which require a dark, humid place with an even temperature. Farmers started to use them in the 19th century and production increased until the middle of the 20th century (the last farmer ended his activity in 1957).
===A refuge===
The quarries have also been marked by the political history of the country as they have been used as a refuge at different times. In the 14th century, bandits and brigands came to hide themselves or their booty in the quarries. In the 16th century, the religious wars between the Protestants in Luxembourg and the Netherlands and the Catholics led by the Spanish in Belgium and the Lille region, were fought. After the defeat of the Catholics, some priests hid their belongings in the quarries and held clandestine masses. They were also used extensively in the 20th century, serving as a refuge for the inhabitants from the German invasion. During the Second World War, many air raid shelters were built, both by the public authorities and by the inhabitants themselves. Even today, old beds and kitchen utensils can be found in the underground tunnels.
===Myths===
It was possible to walk from Lezennes to Tournai. This is a statement that is often heard but which is false. This idea comes from the period between 1713 and 1769 when the commune of Lezennes, which was in French territory, was attached to the bishopric of Tournai (Austrian territory). The myth was then born of an underground passage linking the two communes to pass under the kingdom of France, but this was never the case.
One also sometimes hears the story of a Gallic tribe that disappeared in the quarries of Lezennes. It is known that the Gauls were present in the Lille region as early as the 5th century BC and that they used chalk. However, underground quarries did not yet exist because they worked in open-air quarries.
There is said to be a 'blue lake' in the quarries. In some places, the rock was dug below the water table, so a series of tunnels were flooded, creating a "lake". According to some scientists, its blue colour is due to the presence of small particles ("coccolithophores") that float in suspension when the water is agitated and give the lake a blue appearance. If the water remains still for several years, the particles fall back and the water becomes colourless again.
==Today==
The real estate pressure on the communes around Lille is very important and every day, underground galleries are blocked to allow construction on the surface. The underground tunnels are not classified as "historical monuments", so it is very difficult to avoid the loss of this place full of history. However, action is being taken, in particular by the “Cercle de Recherche Historique de la ville de Lezennes” which has published a book on the history of the quarries and collected all the information about them .