Cardboard boxes cat condo

I just found out about cardboard boxes cat condo on the internet today, did anybody here make one and what does yours look like?

I always feel a bit guilty because we don't have a condo or a cat perch or whatever for our cats. They just hang out with us.

If you look around here, you may find some photos of one or two that our members have made, in addition to the Sterilite box edition.