I often think about what I would do with my outdoor space when I have one someday, and my thoughts immediately go to what surfaces and materials I would use to plan a space. While I love natural stone and slate, I would love to incorporate river rock somehow. Maybe not everywhere, but a faux river rock rug in the dining area could be an interesting way to tie in the concept, and whenever you get tired of it, you can always lay a real outdoor rug over it. No matter what though, you know whoever has the job of painstakingly laying every rock, may want to kill you at the end of the day...
Couldn't resist this little formation of river rock feet!