"Secret room" book

We were talking about book structures over breakfast and I showed Tony how the "ox-plow" structure, folded up, can make a book with a nice space in the middle -

"A space for a panorama?" Well, let's try it out ... So off we went to the park and clambered into the locked bandstand. (It was New Year's Day; do the park police work on holidays?)
Back home, Tony made a template, A3 size - here are the photos of the view from the bandstand on the "outside" pages -
The "room" inside waits for the panorama taken from the centre -
The paper is thick and springy - even the folded cover doesn't keep it from jumping out when you pick it up -
Keeping the inside "room" a secret will depend on using thinner paper - of a quality that allows photo printing on both sides.

I'm planning (someday...) to try this with photos of the four walls of a room inside, and details of objects in the room on the outside pages.