I love the idea by Rudolf Martin in 1908 that Germany could successfully invade Britain by Zeppelin, carrying 350,000 troops in each wave, not the least because of the need to build ~7,000 of them.
I’m trying to imagine how you would hide that preparation. A million acres of camouflage netting? Paint them bright colors and put on a really long air show? Don’t bother to hide it, but try to convince the British you’re actually planning to land in Scotland?
Courtesy of Airminded, a fascinating blog about Airpower and British society, 1908-1941 (mostly).