It was during the construction of the Vennbahn cycle path along the old railway line connecting Aachen, Germany, to Troisvierges, Luxembourg, that bats were first discovered in the tunnel near Huldange.

Protected, the site is home to no less than 13 different species, some of which are quite rare.

Indeed, this tunnel--calm, dark and humid--presents a suitable environment for bats which have found an ideal habitat inside.

In order to help visitors discover the history of this tunnel and its inhabitants, educational panels, audio stations and interactive multimedia terminals have been developed and installed along the “Fledermaustunnel Huldange” discovery trail. The trail is on the cycle path which has been diverted from the tunnel and is comprised of two identical parts, accessibly on both the Luxembourg and Belgian sides.

This article originally appeared in French on Paperjam and has been translated and edited by Delano.