Defensive Fortifications

So in my world the central nation state has a huge moutain range on its one border with several large passes. Each pass is defended by a "wall-fort." Initially I had envisioned something similar to Fort Briggs in Full Metal Alchemist but decided that wasnt quite the direction I wanted to go in. I decided that I would rather have something like the French Maginot Line on steroids. My world has a level of tech similar to the 1920s in our time and given that I realized that my forts could utilize either [retractable turrets](https://youtu.be/vqqVnfGngAI) like the real Maginot Line used, or they could use [disappearing guns](https://youtu.be/MUmkb_g7cx4) which fell out of favor in the early 1900s but were still extensively used. I am leaning toward the disappearing guns mostly because I find them fascinating but also because, unlike in our world, the threat of an air attack is virtually non-existant, the biggest draw back to a disappearing gun over a fully enclosed turret. Either design would significantly change the look /layout of the fort so I wanted to get some more opinions.