Bunker like hi-res stock photography and images - Page 4 - Alamy
The 25tn blast door to Cheyenne Mountain military installation. Designed to withstand a 30 megaton nuclear detonation and able to filter out ABC contaminants. After this door, there is another like it. :
Bunker Air-Filter WWII - 3D Model by KangaroOz 3D
Bunker | Book by Bradley Garrett | Official Publisher Page | Simon & Schuster