350 million years ago, the Kimberley area was part of a large coral reef and the evidence can still be seen in the formation of the numerous limestone gorges and escarpment. Geikie gorge is also home to a large number of wallabies - like rabbits they warn of danger by stamping their feet.

At Tunnel Creek we waded through the water filled caves with our torch. The animal Nic claimed was nibbling at her toes turned out to be a yabbi (small lobster-like freshwater crustacean), and the noise outside the caves was a large gathering of huge fruit bats - they can grow up to 1.6m.

From here we joined the Gibb River Road, an unsealed track still used in the dry season as a short cut for cattle from Derby to Kununurra. The condition of the road was actually disappointingly good! We'd been expecting a real off-road challenge, but apart from some corrugations and a section of deep orange bulldust (right - spot the car!), you don't really need a 4x4.

We camped at Bell Grove in a secluded site next to the river where some friendly turtles came clambering over each other out of the water to greet us. The nearby waterfalls still had some water and a large pool for swimming even though it's late in the dry season.

Further north we crossed the remains of the Pentecost River (left) and saw our first 'crocodile danger' warning signs. We've been in freshwater crocodile territory for a while, but it's the saltwater (estuarine) crocs that are the real danger. From now on anything resembling a floating log should be treated as suspicious and no getting out of the car to check how deep a river crossing is!

Towards the end of the Gibb River Road we stopped off to camp at El Questro - a rather exclusive adventure resort visited by the rich and famous.

We signed up for some horse riding early the next morning we before the heat became too oppressive. The stock horses we were riding were in really good condition and very fast - galloping at the slightest encouragement (aaagh!), not your average stable ponies..

We annoyed the staff by not signing up on one of their expensive 4x4 tours and went off exploring by ourselves. Along a very sandy 4x4 track we came across, amongst other things, a very large baob tree (right) - over 1000 years old.

After a visit to the thermal pools at Zebedee Springs we were back on a sealed road again and on the long trek up to Darwin. We had hoped to visit the Bungle Bungles, but unfortunately they were closed due to bush fires. However, we resolved to come back to this part of the country to drive across the Great Sandy Desert on the Canning Stock Route - one of the most isolated tracks in the world.

We passed through the Gregory National Park which apparently has some challenging off-road tracks and camped in Big Horse Creek. It took us 2 days to reach Darwin, the temperature, humidity and number of flies increasing all the time.

Darwin itself is a very small city, but with a tropical, South East Asian feel - it's only 600 km from Timor. It's also one of those places where you bump into just about everyone you know. We spent a couple of days getting the new springs fitted on the car, visiting the night market (amazing food stalls) and relaxing.

Our next obvious destination was the famous Kakadu National Park, where much of Crocodile Dundee was filmed. The scenery in the park is beautiful and while it wasn't as green as it would have been in 'the wet' the lack of water meant that all the birds and animals were easier to spot as they gathered at the watering holes.

We visited a couple of interesting rock art sites, still a major source of traditional knowledge for the local Aboriginal people as they have no written records of their cultural or historical past. The pictures often depict stories from the 'dreamtime' when the earth was formed and knowledge is handed down from generation to generation in this way.

Much of Kakadu is aboriginal land, leased to the government for use as a national park. There are several aboriginal settlements in the park and about one-third of the park rangers are aboriginal.

Kakadu also has a number of spectacular waterfalls - most of which were dry at this time of year. Access to Jim Jim falls is by 4WD and then a rocky walk to a beautiful plunge pool (the falls were dry). We weren't sure whether it was safe to go in the water or not and there was nobody around to ask so we scared ourselves into being cautious. On the way back we met all the tour groups who were confidently carrying towels and off for a swim - safety in numbers I guess.

Just down the track, Twin Falls can only be reached by swimming several hundred metres up-river. They have nets and traps set for saltwater crocodiles but the notice says you enter the water at your own risk.

We decided to risk it and swam up through the gorge to the beautiful pool complete with sandy beach and almost dry waterfall. We have since heard that the week after we were there a German girl was 'got' by a croc somewhere in Kakadu. Apparently she was swimming at night in a place that she shouldn't have been, but it makes you realise that crocs are a real danger.

The next day we headed out of Kakadu, via Gunlom Falls (the large pool where they did the swimming scene in Crocodile Dundee) and set off 'across the top' towards Cairns.

We followed the road south as far as Daly Waters where we stayed the night in the caravan park and drank in the famous pub - sporting good old Aussie outback jokes such as 'we don't serve women - bring your own' (ho ho ho!).

We then headed east towards the Gulf of Carpentaria,, still on Route 1, but the road had turned into a dirt track. We crossed out of the Northern Territory and into Queensland, stopping at the Hells Gate Roadhouse to refuel and spend the night. Despite the name (it was the last outpost of police protection for settlers and the scene of fierce resistance from local aboriginal people), it's actually a very pleasant place with lots of flowers and large numbers of brightly coloured rainbow lorikeets.

Although remote, the Gulf Savannah with its vast, flat and sparcely populated landscape was an interesting drive. Impassable in the wet, there were still a number of tidal creeks and rivers to cross.

We visited the Undara Volcanic National Park - massive volcanic tubes formed around 190,000 years ago creating the largest lava tube system in the world. Further east we ventured across the Atherton Tablelands - a land of beautiful, green fields with Fresian cows and waterfalls. We swam in crystal clear crater lakes and visited a very large fig tree.

We spent one unfortunate day by the side of the road as one of our wheel bearings let go and in the process welded itself to the stub shaft making it impossible to remove. We ended up sawing through an inch of hardened steel with a little junior hacksaw to get it off - it was a long day!