What is a keyhole garden?
It is a circular shaped garden with a compost basket built at the centre and a small depression towards the centre that al-lows for easy access to the basket and gives the garden a keyhole shape when viewed from above.
The garden uses a number of layers to retain moisture and nourish the soil and the composting basket replenishes the soil's nutrients as well. The garden is made from materials that are locally available at relatively low or no cost.
This document explains how to build your own keyhole garden, complete with pictures.