The other shelter -- we call it the Gucci shelter -- is back further in the woods. It's big enough for three or four cats, although I don't know if Charlie ever has overnight guests there. And it's so heavily insulated, it kept him warm, even when the temperature dropped to seven degrees last week. A man who advertises on Craig's List built it to our specifications especially for the trapped/neutered/returned feral cats who live in our neighborhood.
It seems that different cats have different tastes in shelters. Some of our neighborhood ferals like the Rubbermaid storage boxes we gave them. A friend cut two six-inch holes in the sides, so the cats would have an entrance and an emergency exit if a raccoon or other animal decided to join them inside. The storage boxes have pieces of Styrofoam against the sides, and Mylar, to reflect the cats' body heat, covers the Styrofoam. They're filled with straw, because straw is warmer than blankets and stays dry.
The "Gucci shelter" also has an entrance and emergency exit. There's a shelf inside for added safety and to provide more stretching out space for the cats.
I chose Charlie's shelter because, well... I chose it because that cat face is awfully cute. And I liked that it's off the ground and has an entrance and exit, so my Charlie boy won't get trapped inside. I also liked the awning that keeps snow from piling up at the doors.
Charlie loves it. He can stretch out inside and hold the door open with his head so he can see what's going on outside and when his breakfast and dinner are about to be served. I often find him there just hanging out and relaxing until I show up with his food.
If you live in a cold climate, having a warm shelter can make the difference between life and death for your outside cats. You can read more about DIY cat shelters here.