At the top of Australia, plum in the middle. It's nearer to Singapore than it is to Melbourne and has a curious atmosphere that is both multicultural and very rugged.
Despite its size, Darwin itself retains a small town feel, but on its doorstep are large areas of world-class natural beauty. In and around town, the Museum and Gallery of the Northern Territory, Crocodylus Park and Mindil Beach Sunset Markets are worth a visit.
But Darwin's real importance is as jumping off point for the glorious Kakadu National Park, a region half the size of Switzerland and full of colourful floodplains, rolling bushland, curious rock formations and lots and lots of wildlife. You'll see parrots of many colours, snakes at every turn and plenty of crocodiles; this is the classic outback landscape where Crocodile Dundee lived.
Join a boat ride on the Adelaide River where the deadly reptiles are goaded out of the water by Park Rangers dangling dead chickens under their noses.
Smaller than Kakadau but more tropical and definitely worth a visit is Lichfield National Park (above), known for its many lakes and waterfalls. Heading further down the dusty road that leads ultimately to Alice Springs, two stopping points of note are the dramatic rivers running through Katherine Gorge and the thermal springs of Mataranka.