After recently traveling to Kuming, Yunnan Province I decided to replace the default wallpaper images on my laptop. Below are those images, in full resolution.
They are the exact size you want if you use a 13″ Retina MacBook Pro like I do. They are very high resolution: 2400×1600 pixels at 227 dpi (dots per inch).
Update: a second set of high resolution Australia wallpapers has been added, too.
If you’re on a Mac, the process to change the desktop is System Preferences > Desktop & Screen Saver > then hit the + icon to locate the image(s). I set mine to cycle through the wallpapers once a day automatically.