View through the <a href="https://en.wikipedia.org/wiki/Malpas_Tunnel" class="extiw" title="en:Malpas Tunnel">Malpas Tunnel</a> on the <a href="https://en.wikipedia.org/wiki/Canal_du_Midi" class="extiw" title="en:Canal du Midi">Canal du Midi</a>, France through the western portal.  The tunnel, 173 metres in length, which was Europe's first navigable tunnel was built in 1679.
<a href="//commons.wikimedia.org/wiki/User:Martinvl" title="User:Martinvl">Martinvl</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>