a cat is a cat.
for cats - an alternate path down the stairs
We grew some grass for our (indoor) cat. We think she likes it. - Imgur | good idea for the fosters.
Window cat door and cat aviary for inside cats.. could even keep the cat box out there.
Hey, I found this really awesome Etsy listing at https://www.etsy.com/listing/238683052/window-cat-hammock-with-cushion More
DIY Cat Tree - This one may be a little ambitious for me but it's so great I had to post it!
Cat Tree Plans: Build Cat Condo Furniture, Window Perch, Cat Scratching Post & More by Brian Johnson, http://www.amazon.com/dp/B00802JDPS/ref=cm_sw_r_pi_dp_G9gmsb1K2GQXY
Decided to try my hand at building my own cat tree.
Vintage suitcase bunk pet -bed. I would think you could also turn them the other way and use as a table. More