Reichsbahn Tunnel near Frechenhausen

Routing note: Komoot always routes the route from the tunnel to Breitscheid via the main road because the old track in the area of the Cartonia company is private property. However, the municipality of Breitscheid has recently graveled the old railway line, so you only have to follow the direction of the remaining tracks.
The lighting is great.
Dogs should definitely be kept on a leash in the tunnel; despite the lighting, it is difficult to see a dog.
However, it is still advisable to have a light with you so that you can be seen.
During the winter months, the tunnel is closed off with gates because of the bats in the tunnel.

That's how it used to be: (Transit not necessarily recommended.
Pretty creepy but interesting. If you are planning your tour through this tunnel, you should consider that 1. there is only loose gravel here and it is not easy to drive and 2. it has no lighting.)
Addendum 2022: Tunnel is now nicely paved, well lit and highly recommended 👍🏼

Interesting structure. Of course without light on the way, the mobile phone flashlight at least brought some light into the tunnel. It seems like the tunnel never ends.