This 'ible was heavily influenced and inspired by supersoftdrinks awesome Cardboard Play Dome she made for her kids. (Can be found in https://www.instructables.com/id/Cardboard-Play-Dome/
) I was impressed and wanted to make one myself, but as an "adult" it would have had to be huge and it would take a lot of space from our small apartment. Still, I wanted to do this, and I thought to myself: "If I only had kids to make this to, they'd think I'm an awesome mother." Then I realized, petting our newly rescued cat, that I had someone to make this to.
Our cats first walked around it, the braver one finally got cozy in it in the evening. I still have to add something soft inside for them to lay on, and paint the whole thing as soon as I get the right paint.