I love Darwin. It has some really interesting WW2 history but you wouldn't have been interested in it at age 18. I've visited 3 times. Once on our way to Singapore. Once for a week away from the business. And once with the kids. We hired a car that time and didn't spend much time in Darwin itself. The worst thing about Darwin is the heat and humidity. Everywhere is aircon but as soon as you walk outside it hits you like a brick wall.