A keyhole garden is a type of compost garden that originated in Africa. Biodegradable scraps go in the middle, and the plants all around are fed well. I have converted the basic concept of the design into a landscaping asset for architectural rendering with a PBR setup in Cycles.

To use this model, append it as the GROUP (NOT individual objects) Keyhole Garden into your scene. All objects are parented to the Keyhole Garden Bricks object for easy positioning. The model has physically-based shader setups, complete UV maps, and is ready to be rendered upon purchase (unless custom work is desired).