A Tunnel to the sea ! A late 70’s Czechoslovakian project to link Czechia to the Adriatic Sea.
A bit of reading :
[https://worksthatwork.com/2/tunnel-to-the-other-side](https://worksthatwork.com/2/tunnel-to-the-other-side)
[https://returntoadriaport.wordpress.com/2019/01/15/the-adriatic-sea-tunnel/](https://returntoadriaport.wordpress.com/2019/01/15/the-adriatic-sea-tunnel/)
Basically it was a project to end the landlock situation of Czechoslovakia
by tomydenger