To download, left click on the image. Then right click on the larger image. Click "Save image as..." and save it to your desktop or some such place. Then, go to that place and double click on the file. Right click on the image and select "Set as Desktop Background". Go to your desktop and wait a few seconds, or push F5.
This is a park scene BusyCityGuy modeled in his spare time. (Not a world)