What did the Germans hide inside this WWII hill ? Secret project or just hidden in plain sight..

What did the Germans hide inside this WW2 hill ? Why so much effort to defend this very special location.. Our unique videos takes a ton of time to create so If you like to support our work : My Email : ww2historyhunter@ Check out our monthly WW2 diorama giveaway videos in the beginning of each month. Beautiful WW2 dioramas for my supporters. Check out these incredible Robotics skills : My underwater exploration gear : QYSea Fifish V6S & V6 and Fifish V6 Expert. With a gripper to recover artifacts from the deep ! Omni directional and totally awesome for underwater exploration ! Our flashlight gear :