when my kitty was little, my brother made her a 3-story cardboard house, with stairs, secret rooms, a ton of little spy-windows, that she could spy out of, or catch curious fingers out of w her paw
when we moved from there, we trashed it :/ it was enormous tho, we shared an apartment. we couldnt bring it w us to a flat. she loooooved it tho
she totally used the little secret compartments as well
and peeked out the spy-holes