This is not a joke. In Norway they have actually conducted research for the treatment of tunnel phobia. I did not know if such a phobia even existed. I reckon people in Norway are used to living outdoors in nature unlike us who are used to traveling in subways from our childhood in grey big cities.

Here you are:

Treatment of Tunnel Phobia: An Experimental Field Study

K Gunnar Gotestam, Sven Svebak

Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway.

https://pubmed.ncbi.nlm.nih.gov/19440895/