Qualcuno sa dei tunnel sotto Tigne Point?

Hii, quick follow-up question:

We visited the tigne point and its beaches today and were wondering, what the tunnels and rails were used for? We tracked on tunnel to the location marked in the second image but werent sure about its purpose?
Ive read quite a lot about fort tigne now (*) but am still not any smarter – any ideas ? 🙂

(*)

[https://archive.ph/20160817163252/http://www.militaryarchitecture.com/index.php/Building-Methods/fort-tigne-1792.html](https://archive.ph/20160817163252/http://www.militaryarchitecture.com/index.php/Building-Methods/fort-tigne-1792.html) (Fort Tigne History Part I)

[https://archive.ph/rZEUl](https://archive.ph/rZEUl) (Part II)

[https://archive.ph/DLE6k](https://archive.ph/DLE6k) (Part III)