1) Street signs (already made of metal and to resist the weather! Just obtain legally, please!) as spotted in Reuben & Paul's Rancho Reubidoux.
2) Vintage metal wall art, as seen in Maggie B's Slowly Designed Space.
3) John's Lovely & Lush Backyard Retreat features a lovely over-sized mirror.
4) Reused architectural elements, like this window spotted in the post A DIY Concrete Block Planter & Bar.
5) Take plants and their color vertical with a living wall!
Need more ideas? How about actual art that's weatherproof, like paintings on aluminum (we've spotted some on Etsy, like California Landscape Art on Aluminum). Or what about a pattern or quote written in moss on a wall, a fun DIY project?
What kind of art do you have in your outdoor space?
(Images: Maggie, Rancho Reubidoux, Bethany Nauert, The Hunted Interior, GSky Plant Systems)