When I was seven and a half months pregnant I flew to Alice Springs, or Mparntwe - its Arrernte name.

My husband Henry was running wildlife photography tour in the area, and we planned to drive back to Sydney, camping along the way, to pack in as much adventure as possible before our son Freddie arrived!

It was one of my favourite trips ever. Even though sleeping in freezing conditions on the ground, SO pregnant, got a bit uncomfortable towards the end, it was TOTALLY worth it.

One of the stops we made before starting the journey south and east were the Ochre Pits in the West MacDonnell Ranges, 110km west of Alice Springs.

This very special place has been used by the Western Tjoritja Aranda people for thousands of years. Only men can extract ochre from the site, and women and children can use it with the men's permission.

Different colours are used for different occasions. Yellow and white, for example, mixed with water and animal fat, make a paste for decorative uses. Red features more in ceremonies and also combined with leaves as a type of medicine. It was also a highly prized trading piece.

On a more scientific level, different colours occur because of varying levels of iron oxide (or rust) in the clays. The more iron, the redder. And the more subdued the colours, the less iron! 

And if you're up for a bit of of a geology lesson, I can tell you this beautiful material was created hundreds of millions of years ago when mud and sand settled at the bottom on an ancient sea. And about 300 million years ago the floor of the inland sea pushed up vertically. This actually created the MacDonnell Ranges, and exposed the mud and siltstone of the ochre pits.