<div style="text-align:center"><span class="language en" title="English"><b><a href="https://en.wikipedia.org/wiki/English_language" class="extiw" title="w:English language">English</a></b> (en):</span> </div>
<div class="legend" style="direction:ltr;line-height:23px;"><div class="legend-content" style="display:inline-block;vertical-align:top;box-sizing:border-box;width:34px;height:23px;overflow:hidden;font-size:15px;border:thin solid #333;background:#95C957;color:#202122;text-align:center;"> </div> Underground gypsum exploitations</div><div class="legend" style="direction:ltr;line-height:23px;"><div class="legend-content" style="display:inline-block;vertical-align:top;box-sizing:border-box;width:34px;height:23px;overflow:hidden;font-size:15px;border:thin solid #333;background:#F1A18A;color:#202122;text-align:center;"> </div> Underground limestone exploitations</div>
<p>Plan: Émile Gérards (1859–1920) <a rel="nofollow" class="external text" href="http://catalogue.bnf.fr/ark:/12148/cb12233342w/PUBLIC">BnF Notice d'autorité personne</a>
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<br>Digital copy: <a href="//commons.wikimedia.org/wiki/User:ThePromenader" title="User:ThePromenader">ThePromenader</a>
<span class="int-own-work" lang="en">Own work</span>