There's an intentionally secret / hidden cave in A Coruña' city in Spain. Is there any information about it anywhere ?

-  It's on public land, right next to, and below, the [https://en.wikipedia.org/wiki/Aquarium_Finisterrae][1] but does not seem to be in any way connected to the Aquarium Finisterrae.

-  It has had two large boulders intentionally placed in front of it, so that fewer people will notice it.

-  At some time, a square window was cut into the very thick side of the cave .

- It does not seem to be mentioned anywhere on the internet [https://es.wikipedia.org/wiki/Playa_de_Las_Lapas][2]

Unfortunately I cannot obtain better photos of it.     
When looking at it in person from the other side of the bay, you can clearly see it is a cave, and the window .    
      
is there any information about it anywhere ?

[![enter image description here][3]][3]

[![enter image description here][4]][4]


  [1]: https://en.wikipedia.org/wiki/Aquarium_Finisterrae
  [2]: https://es.wikipedia.org/wiki/Playa_de_Las_Lapas
  [3]: https://i.sstatic.net/RLaRl.png
  [4]: https://i.sstatic.net/vo9Lf.png