If you ever find yourself in western PA, I can arrange a visit. It’s kind of freaky. Imagine building a home from scratch with cats in mind. The place houses 70 - 100 cats.
Many houses in Florida have what looks like that catio in kayaker’s pic. But it’s not for cats; at least not primarily.
Instead it encloses the entire patio, BBQ, and pool area in a fine mesh screen so you’re not sucked dry by mosquitos in the first 30 seconds of enjoying the fine tropical sunshine.
The fact it keeps the gators from eating Cuddles, Fluffy, Fideaux, Pwecious, *and *your toddlers is only a plus. 
I would enjoy that - I just watched a video on their facebook page. and now, excuse me, I have something in my eye.
it now seems weird and sick to me that we usually keep homeless cats in small metal cages, WTH
A house in our neighborhood used to have a little screened-in gazebo, about 2 feet square, mounted atop the home’s 6-foot cinder block wall. Every so often we’d see the owner’s Pekinese watching the world go by from inside it. There was a ramp on the inside of the wall so the dog could get to his viewing post.
Chicken wire comes in different guages, and the stuff that’s advertised as fox proof should be fine for cats. Doesn’t harm my cats, anyway (I have no cation but I do have chickens).
To prevent them going onto a busy road, maybe?