Purnululu National Park, also known as "The Bungle Bungles" is situated in the Kimberley region of northern West Australia. The main geological features of the area are the distinctive eroded domes, and Piccaninny Creek, which has cut a deep gorge through the main plateau. The creek itself is usually dry during winter, and this walk follows the creek and its tributaries, with an extra day walk out to the east on the last day. Navigation in the main gorge is pretty easy. Bear in mind that the creek can flood very quickly, so don't go if rain is forecast.
There are five main tributary gorges, arranged a bit like the fingers and thumb of your right hand. Access to the lower end of each tributary from the main gorge is usually pretty easy, but some are a narrow squeeze in their upper parts and may even involve a swim in fairly cool water. Progress along each tributary is usually arrested by a cliff or impassable outcrop at some pointWhile Piccaninny Creek is the main tourist attraction (you'll probably be accompanied by he occasional sounds of light aircraft as you walk along it), the open country to the east is quite different and also worth a visit.
I did this walk over five days in the winter of 2000 with a commercial tour operator. They had their own vehicles, which solved the main transport problem of getting from Kununurra (the closest main town) to the start of the walk and back out again five days later.
You can fly in to Kununurra and stock up on most groceries there. It's probably wise to check the availability of your particular stove fuel first - even methylated spirits. You can probably hire a four-wheel-drive vehicle there, but a cheaper option might be to organise with one of the local tour operators to drop you off and pick you up again a few days later. Even if you have to pay for two round trips it may be cheaper than hiring a 4WD for a week.
You will definitely need a four-wheel-drive vehicle to get to the start of the walk. It's about 300km from Kununurra, with the last section on unsealed roads with at least one tricky creek crossing thrown in for good measure. It took more than half a day to drive in.