This has been a monument to the Slow Food movement. Early last year we took river stone from the Hutt River (it's legal). After that, I phoned about 12 different people and eventually came up with a free supply of clay which was dry enough to load into the car. Next we scored some terracotta tiles and some sand from our friends. Finally, we got some pea straw - that cost $15.
Step 1 was to cement together the river stone so that we had a platform the same height as the top terrace.
Step 2 was to stick the terracotta tiles to the surface of the platform with clay.
Step 3 was to build a sand mountain over which to layer the clay and sand mixes.

Step 4 was to cover the sand layer in a clay and sand mix.

Step 5 was to cover this layer with the sand, clay and pea straw mixture.

Step 6 was the final layer of clay and sand.

Step 7 was to dig out the door then dig out the sand mountain from inside the oven so that the clay could dry out.
Step 8 was to light a gentle fire to help the drying process.

Step 9, make bread.

The oven didn't get hot enough. We still need to fashion a reasonably tight-fitting door to keep the heat in, I think this will make alot of difference. I also think that leaving the embers in the oven and just pushing them to the sides will help with keeping the oven's thermal mass hot enough. There is much experimentation ahead. Hopefully we will have it sorted before the tomatoes are ripe for the picking.