Lots of people have a patio with a roof or cover on it that can be turned into a catio.

All it takes is a little framework, shelves for perches, and either wire or polyester screening.  This catio uses black TuffScreen which is strong enough to keep kitties in, fine enough to keep insects out, and light enough to offer great visibility out into the yard from inside the catio.

Lots of perches mean that everyone can get a prime spot.

And the kitties seem to agree!

These kitties did miss one thing, though - they really liked climbing trees.  So I found a way to let them do that while still being safe and secure inside their catio ;o)