A well fed spider

I walked up the steps from the patio to the house and noticed this rather large spider. When I returned with a camera and looked closely I could see the web was very fragmented as if there had been many trapped insects on it in recent times. 

The spider didn't move, even as I got very close up. Its head and upper body were pointing at the wall so possibly it was asleep or just didn't notice me. I don't remember seeing one of such a shape or colour before. I'd guess it was at least an inch and a half in diameter if not more, including it legs/arms.