Here is another pretty cool idea to upcycle any old doors you might come across or just have lying around your home. They can easily be upcycled into a patina-rich arbor walkway for your yard. All you need is a saw, drill, and a couple of extra boards. You also don't have to stick with this particular design and could pretty much construct the top however you see fit.
While this person used a couple of interior brackets to stabilize the bottom, you could easily switch it up with some small boards or antique brackets to keep with the look.