Military secrets and the engineering behind them, cut open in 3D: hidden bases, Cold War spy projects, aircraft carriers, submarines and the machines nobody was supposed to see inside.

Every video opens one file: how it was built, how it actually works and what it was really for. Each machine and place is rebuilt in 3D so you can see inside it.

Scripts are researched from declassified documents, technical manuals and published histories, and the sources are listed under every video. If something is wrong, say so in the comments and the correction gets pinned.

New file every week.